JP2007227438A - Exposure apparatus and exposure method, and mask for light exposure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exposure apparatus or the like which can reduce the frequency of stage acceleration/deceleration without inducing a large increase in cost and can improve exposure accuracy as a result. <P>SOLUTION: The exposure apparatus EX is provided with a rotatable reticle R which has a pattern to be transferred to a wafer W as an object to be exposed, and a wafer stage WST which can move in an XY plane while holding the wafer W. The reticle R is cylindrical or columnar, for example, and a pattern to be transferred to the wafer W is formed on its circumferential surface. A main control MC synchronizes the rotation of the reticle R with the movement of the wafer stage WST, and controls the transfer of the pattern formed on the reticle R onto the wafer W at the same time. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an exposure apparatus and method for exposing and transferring a pattern formed on a mask onto a substrate, and an optical exposure mask.

  In the manufacture of microdevices such as semiconductor elements, liquid crystal display elements, imaging devices (CCD (Charge Coupled Device), etc.), thin film magnetic heads, etc., they are formed on masks and reticles (hereinafter referred to as masks when these are collectively referred to). An exposure apparatus is used that transfers a pattern onto a wafer or a glass plate or the like (hereinafter referred to as a substrate when collectively referred to as a substrate) coated with a photosensitive agent such as a photoresist. In recent years, step-and-repeat type reduction projection exposure apparatuses (so-called steppers) or step-and-scan type exposure apparatuses (so-called scanning steppers) are frequently used.

  In the above stepper, the substrate is placed on a substrate stage that is movable in two dimensions, and the substrate is stepped (stepped) by this substrate stage, and a reduced image of the mask pattern is applied to each shot area on the substrate. An exposure apparatus that sequentially repeats the batch exposure operation. Further, the scanning stepper moves (scans) the mask stage on which the mask is placed and the substrate stage on which the substrate is placed in synchronization with each other while the mask is irradiated with elongated rectangular (slit) pulse exposure light. Then, a part of the pattern formed on the mask is sequentially transferred to the shot area of the substrate, and when the transfer of the pattern to one shot area is completed, the substrate is stepped in a direction crossing the scanning direction to another shot area. An exposure apparatus for transferring a pattern.

  In the above scanning stepper, each time exposure of one shot area is completed, the scanning process of the mask stage and the substrate stage is reversed, and the exposure process is sequentially performed. That is, plus scan and minus scan are alternately repeated for each shot area. For this reason, the scanning stepper performs acceleration / deceleration of the mask stage and the substrate stage each time the shot area is exposed.

  Here, in order to improve the exposure accuracy, it is desirable to start the exposure process after the vibration generated after the acceleration is finished and both stages are at a constant speed and sufficiently synchronized. For this purpose, it is necessary to secure to some extent the settling time (the time required for the speed of each stage to converge after the acceleration of each stage is converged). However, in the scanning stepper, since acceleration and deceleration are repeated, if the settling time is increased, the throughput (the number of wafers that can be processed per unit time) is directly reduced. For this reason, it is not easy for the scanning stepper to improve both the exposure accuracy and the throughput. In recent years, the substrate tends to increase in area in order to improve the device manufacturing efficiency and reduce the device manufacturing cost. Therefore, it is desired to reduce the number of times of acceleration / deceleration of the stage.

  In Patent Document 1 below, a reticle in which a plurality of patterns to be transferred to different shot areas is used, and the reticle is synchronously moved in the pattern arrangement direction to expose a plurality of shot areas in one scan. An exposure apparatus is disclosed. In such an exposure apparatus, the number of stages of acceleration / deceleration of the stage can be reduced to a fraction of the number of patterns formed on the reticle (for example, 1/2 when two patterns are formed). A decrease in synchronization accuracy due to acceleration / deceleration can be reduced and the throughput can be improved.

Further, in Patent Document 2 below, first and second reticle stages are provided, and the first reticle stage moves in the opposite direction while the first reticle stage is scanning, so that the first reticle stage An exposure method is disclosed in which exposure using a second reticle stage is performed in conjunction with continuous movement of the wafer stage after scanning is completed. In such an exposure method, it is possible to expose one row of shot areas among shot areas set on the wafer without acceleration / deceleration of the wafer stage.
JP-A-10-284411 Japanese Patent No. 353297

  By the way, in Patent Document 1 described above, in order to reduce the number of times of acceleration / deceleration of the stage, it is necessary to form many patterns on the reticle. For this reason, there is a problem that the reticle is increased in area and the cost required for the production of the reticle is extremely increased. Further, since this large-area reticle is used, there is a problem that the reticle stage is enlarged and the cost of the exposure apparatus is increased.

  In the above Patent Document 2, it is necessary to provide a plurality of reticle stages and to form a reticle to be placed on each reticle stage. In addition, it is necessary to provide an optical system for projecting an image of the pattern of the reticle placed on each reticle stage onto the wafer. Further, it is necessary to synchronize the reticle stage and the wafer stage as well as the reticle stages. For this reason, there is a problem that the cost of the exposure apparatus is significantly increased, and the cost of reticle production is doubled.

  The present invention has been made in view of the above circumstances, an exposure apparatus capable of reducing the number of times of acceleration / deceleration of the stage without causing a significant increase in cost, and as a result, improving the exposure accuracy and It is an object to provide a method and an exposure mask.

The present invention adopts the following configuration corresponding to each diagram shown in the embodiment. However, the reference numerals with parentheses attached to each element are merely examples of the element and do not limit each element.
In order to solve the above problems, an exposure apparatus according to the present invention is rotatable in an exposure apparatus (EX) that exposes and transfers a predetermined pattern to an object to be exposed (W), and has a pattern to be transferred to the object to be exposed. A mask (R), a stage device (WST) capable of holding and moving the object to be exposed, and a control device (MC) for synchronously controlling rotation of the mask and movement of the stage device. It is said.
According to the present invention, the pattern formed on the mask is transferred by moving the object to be exposed in synchronization with the rotation of the mask.
In order to solve the above problems, an exposure method of the present invention is an exposure method for exposing and transferring a predetermined pattern to an object to be exposed (W), and a rotatable mask (R) having a pattern to be transferred to the object to be exposed. ) Is rotated in synchronization with the movement of the object to be exposed, and the mask pattern is transferred to the object to be exposed.
In order to solve the above-mentioned problems, a photoexposure mask according to the present invention is a photoexposure mask (R) used for transferring a predetermined pattern to an object to be exposed (W). It has a pattern (P, P ′, P1, P2) to be transferred, and is characterized by being one of a cylindrical shape and a columnar shape.

  According to the present invention, since exposure processing is performed using a rotatable mask on which a pattern is formed, when performing exposure processing while reciprocating a conventional mask, a plurality of stages for holding the mask are provided. Compared to the case, the cost of the exposure apparatus is not significantly increased. In addition, according to the present invention, the pattern can be transferred to a plurality of locations on the exposed object by continuously rotating the mask and moving the exposed object in one direction. Can be reduced. As a result, the exposure accuracy can be improved.

  Hereinafter, an exposure apparatus and method and an optical exposure mask according to embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 is a front view showing a schematic configuration of an exposure apparatus according to the first embodiment of the present invention. As shown in FIG. 1, the exposure apparatus EX of the present embodiment illuminates a reticle driving mechanism RM that drives a reticle R as a mask, a wafer stage WST that holds a wafer W as an object to be exposed, and the reticle R with exposure light EL. Mainly controls the overall operation of the illumination optical system ILS, the projection optical system PL that projects the pattern image of the reticle R illuminated by the exposure light EL onto the wafer W held on the wafer stage WST, and the exposure apparatus EX as a whole. A control system MC is included.

  In addition, the exposure apparatus EX of the present embodiment is an immersion type exposure apparatus to which an immersion method is applied in order to improve the resolution by substantially shortening the exposure wavelength and substantially increase the depth of focus. The liquid supply mechanism SW for supplying the liquid Lq onto the wafer W and the liquid recovery mechanism CW for recovering the liquid Lq on the wafer W are provided. The exposure apparatus EX is on the wafer W including the projection region PR of the projection optical system PL by the liquid Lq supplied from the liquid supply mechanism SW during at least the exposure operation for transferring the pattern of the reticle R onto the wafer W. A liquid immersion region WR is formed in a part. Specifically, the exposure apparatus EX fills the space between the optical element 1 at the front end (end portion) of the projection optical system PL and the surface of the wafer W with the liquid Lq, and the reticle via the projection optical system PL and the liquid Lq. The R pattern image is projected onto the wafer W to expose the wafer W.

  An exposure apparatus EX shown in FIG. 1 is a scanning exposure apparatus (a so-called scanning stepper) that transfers a pattern formed on a reticle R onto a wafer W while moving the reticle R and the wafer W synchronously. Although details will be described later, since the reticle R used in the exposure apparatus EX of the present embodiment is rotatable, the rotation of the reticle R is controlled to synchronize with the movement of the wafer W. In the following description, an XYZ orthogonal coordinate system is set in the drawing as needed, and the positional relationship of each member will be described with reference to this XYZ orthogonal coordinate system. The direction that coincides with the optical axis AX of the projection optical system PL is the Z-axis direction, and the synchronous movement direction (scanning direction) between the reticle R and the wafer W in the plane perpendicular to the Z-axis direction is the Y-axis direction, Z-axis direction, and Y A direction (non-scanning direction) perpendicular to the axial direction is set as the X-axis direction. Further, the rotation (inclination) directions around the X, Y, and Z axes are set to the θX, θY, and θZ directions, respectively.

  The exposure apparatus EX includes a main column 2 that supports the reticle driving mechanism RM and the projection optical system PL. The main column 2 is installed on a base plate 3 placed horizontally on the floor surface. The main column 2 is formed with an upper step 2a and a lower step 2b that protrude inward. The illumination optical system ILS is supported by a support column 4 fixed to the upper part of the main column 2. The illumination optical system ILS illuminates the reticle R with the exposure light EL, and condenses the exposure light EL from the exposure light source, the optical integrator that equalizes the illuminance of the light beam emitted from the exposure light source, and the optical integrator. A condenser lens, a relay lens system, and a variable field stop for setting the illumination area on the reticle R by the exposure light EL in a long and narrow rectangular shape (slit shape).

  Further, the exposure apparatus EX of the present embodiment irradiates the exposure light EL emitted from the illumination optical system ILS onto a reticle R having a cylindrical shape or a cylindrical shape (hereinafter, these shapes are collectively referred to as a cylindrical shape). A reflection optical system is provided. FIG. 2 is a side view showing a reflective optical system that irradiates exposure light EL onto a cylindrical reticle R. FIG. As shown in FIG. 2, the reflection optical system 40 is disposed between the cylindrical reticle R and the projection optical system PL, and includes a first cylindrical lens 41, a bending mirror 42, and a second cylindrical lens 43. Composed.

  The first cylindrical lens 41 corrects the shape of the slit-shaped exposure light EL emitted from the illumination optical system ILS. The bending mirror 42 deflects the exposure light EL that passes through the first cylindrical lens 41 and travels in the −Y direction toward the reticle R. Here, the bending mirror 42 deflects the exposure light EL toward the lowermost part BT of the cylindrical reticle R. The second cylindrical lens 43 corrects the shape of the exposure light EL deflected by the bending mirror 42. That is, the slit-shaped exposure light EL emitted from the illumination optical system ILS is corrected by the first cylindrical lens 41 and the second cylindrical lens 43 into a linear shape extending in the X direction or a slit shape having a predetermined width. Then, the lowermost part BT of the cylindrical reticle R is irradiated. Thus, the reflective optical system 40 reflects and illuminates the reticle R.

  The lowermost BT of the reticle R is disposed at the focal position on the object side of the projection optical system PL. On the other hand, the surface of the wafer W is disposed at the focal position on the image side of the projection optical system PL. That is, the reticle R is arranged so that its lowermost part BT is conjugate with the surface of the wafer W with respect to the projection optical system PL. In this embodiment, it is assumed that an ArF excimer laser (wavelength 193 nm) is provided as an exposure light source. Further, as the liquid Lq supplied between the projection optical system PL and the wafer W, pure water that absorbs less ArF excimer laser light is used.

  FIG. 3 is a view showing the reticle R used in the first embodiment of the present invention. As shown in FIG. 3A, the cylindrical reticle R is rotatable around the central axis CX. Further, as developed and shown in FIG. 3B, a plurality of pattern formation areas PA are provided along the circumferential direction of the reticle R, and transferred onto the wafer W in each of the pattern formation areas PA. A power pattern P is formed. FIG. 3B is a development view when the circumference of the reticle R is viewed from the inside in the direction from the Y axis to the Z axis (clockwise when viewed from the −X direction to the + X direction). The pattern P is obtained by patterning a metal film made of, for example, chromium (Cr) or the like into a predetermined shape, and its planar shape is similar to the pattern transferred to the shot area on the wafer W. In the following, for the sake of simplicity, it is assumed that the pattern P has the shape of the letter “F”.

  The first reason for providing a plurality of patterns along the circumferential direction of the reticle R is to reduce the curvature of the pattern by increasing the radius of curvature of the reticle R. The second reason is to increase the moment of inertia of the reticle R to stabilize the rotation of the reticle R. The third reason is to reduce the number of times of acceleration / deceleration of wafer stage WST. In other words, if the acceleration / deceleration of wafer stage WST is performed each time each shot area set on wafer W is exposed, it is difficult to achieve both improvement in exposure accuracy and improvement in throughput. For this reason, a plurality of patterns P are provided along the circumferential direction of the reticle R in order to expose as many shot regions as possible by one scan. In the example shown in FIG. 3B, for the sake of simplicity, an example in which four patterns P are formed in the circumferential direction of the reticle R is shown. It is desirable to form the maximum number of patterns P in the Y direction (scanning direction).

  The reticle drive mechanism RM is supported on the upper step 2a of the main column 2, holds the reticle R so that the central axis CX is along the X direction, and can be rotated around the central axis CX. Hold R. The reticle drive mechanism RM can rotate the reticle R in one direction at a constant speed, can reverse the rotation direction of the reticle R, and can be rotated around the Y axis and the Z axis (θY, θZ). The fine rotation of the reticle R is possible. The reticle drive mechanism RM holds the reticle R in an exchangeable manner. For example, a portion (holding portion) that holds the reticle R of the reticle drive mechanism RM is configured to be movable in the ± X directions, and the reticle R can be exchanged by moving the holding portion. More specifically, the reticle R can be held by sandwiching the upper and lower bottom portions of the cylindrical reticle R from the ± X directions by narrowing the interval between the holding portions arranged at both ends of the reticle R. The holding of the reticle R is released by widening the interval between the holding portions, whereby the reticle R can be exchanged.

  Further, the reticle drive mechanism RM is provided with a rotation detection device 5 such as a rotary encoder that detects the amount of rotation of the reticle R. The rotation detection device 5 detects the amount of rotation of the reticle R in real time, and the detection result is output to the main control system MC. The main control system MC performs synchronous control between the wafer W and the reticle R by controlling the rotation amount of the reticle R based on the detection result of the rotation detection device 5.

  The projection optical system PL projects the pattern image of the reticle R onto the wafer W at a predetermined projection magnification β, and includes a plurality of optical elements including an optical element (lens) 1 provided at the front end portion on the wafer W side. The element is configured to be supported by a lens barrel PK. In the present embodiment, the projection optical system PL is a reduction system having a projection magnification β of, for example, 1/4 or 1/5. Note that the projection optical system PL may be either an equal magnification system or an enlargement system. A flange portion FLG is provided on the outer peripheral portion of the lens barrel PK. A lens barrel surface plate 7 is supported on the lower step 2 b of the main column 2 via a vibration isolation unit 6. The projection optical system PL is supported by the lens barrel base plate 7 by engaging the flange portion FLG of the projection optical system PL with the lens barrel base plate 7. In the present embodiment, it is assumed that the projection optical system PL projects an inverted image of the pattern formed on the reticle R onto the wafer W.

The optical element 1 provided at the tip of the projection optical system PL is detachably attached to the lens barrel PK. The optical element 1 with which the liquid Lq in the immersion area WR comes into contact is formed of meteorite (calcium fluoride: CaF ₂ ). Since meteorite has high affinity with water, the liquid Lq can be brought into close contact with almost the entire liquid contact surface of the optical element 1. Thereby, the optical path of the exposure light EL between the optical element 1 and the wafer W can be reliably filled with the liquid Lq. The optical element 1 may be quartz having high affinity with pure water. Further, the liquid contact surface of the optical element 1 may be subjected to a hydrophilization (lyophilic process) to further increase the affinity with the liquid Lq.

  A plate member 8 is provided around the optical element 1 so as to surround the optical element 1. The plate member 8 is provided in order to satisfactorily form the liquid immersion region WR over a wide range, and the surface (that is, the lower surface) facing the wafer W is a flat surface. The lower surface (liquid contact surface) of the optical element 1 provided at the distal end portion of the projection optical system PL is also a flat surface, and is arranged so that the lower surface of the plate member 8 and the lower surface of the optical element 1 are substantially flush. . Similar to the optical element 1, the lower surface of the plate member 8 can be subjected to surface treatment (lyophilic treatment).

  Wafer stage WST is configured to be movable while adsorbing and holding wafer W via substrate holder 9, and a plurality of gas bearings (air bearings) 10 which are non-contact bearings are provided on the lower surface thereof. A substrate surface plate 12 is supported on the base plate 3 via a vibration isolation unit 11. Air bearing 10 has an air outlet that blows out gas (air) to the upper surface (guide surface) of substrate surface plate 12, and an air inlet that sucks the gas between wafer stage WST lower surface (bearing surface) and the guide surface. And a constant gap is maintained between the lower surface of wafer stage WST and the guide surface by a balance between the repulsive force due to the blowing of gas from the air outlet and the suction force due to the air inlet.

  That is, wafer stage WST is supported in a non-contact manner on the upper surface (guide surface) of substrate surface plate (base member) 12 by air bearing 10, and light of projection optical system PL is emitted by a substrate stage drive mechanism such as a linear motor. It can be moved two-dimensionally in a plane perpendicular to the axis AX, that is, in the XY plane, and can be slightly rotated in the θZ direction. Further, the substrate holder 9 is provided so as to be movable in the Z-axis direction, the θX direction, and the θY direction with respect to the wafer stage WST. The substrate stage drive mechanism is controlled by the main control system MC. That is, the main control system MC controls the substrate holder 9 via the substrate stage driving mechanism, and controls the focus position (Z position) and the tilt angle of the wafer W so that the surface of the wafer W is auto-focused and auto-leveling. To match the image plane of the projection optical system PL.

  A movable mirror 13 is provided on wafer stage WST (substrate holder 9), and a laser interferometer 14 is provided at a position facing movable mirror 13. The two-dimensional position and rotation angle of wafer W on wafer stage WST are measured in real time by laser interferometer 14, and the measurement result is output to main control system MC. The main control system MC performs positioning of the wafer W supported by the wafer stage WST by driving a substrate stage driving mechanism including a linear motor based on the measurement result of the laser interferometer 14.

  An auxiliary plate 15 is provided on wafer stage WST (substrate holder 9) so as to surround wafer W. The auxiliary plate 15 has a flat surface substantially the same height as the surface of the wafer W held by the substrate holder 9. By providing the auxiliary plate 15, even when the edge region of the wafer W is exposed, the liquid Lq is held under the projection optical system PL by the auxiliary plate 15 and the wafer W. Further, a recovery port 16 connected to a recovery device (not shown) that recovers the liquid Lq that has flowed out of the wafer W is provided outside the auxiliary plate 15 on the upper surface of the substrate holder 9. The recovery port 16 is an annular groove formed so as to surround the auxiliary plate 15, and a liquid absorbing member made of a sponge-like member, a porous body, or the like is disposed therein.

  Wafer stage WST is supported by X guide stage 17 so as to be movable in the X-axis direction. Wafer stage WST is movable with a predetermined stroke in the X-axis direction by X linear motor 18 while being guided by X guide stage 17. At both ends in the longitudinal direction of the X guide stage 17, a pair of Y linear motors 19 that can move the X guide stage 17 along with the wafer stage WST in the Y axis direction are provided. A gas bearing (air bearing) that is a non-contact bearing is interposed between the stator of the Y linear motor 19 and the flat portion of the guide portion 20, and the stator of the Y linear motor 19 is guided by the air bearing. It is supported in a non-contact manner with respect to the flat portion.

  Further, on both sides of the substrate surface plate 12 in the X-axis direction, guide portions 20 that are formed in an L shape in front view and guide the movement of the X guide stage 17 in the Y-axis direction are provided. The guide part 20 is supported on the base plate 3. On the other hand, a concave guided member 21 is provided at each of both longitudinal ends of the lower surface of the X guide stage 17. The guide portion 20 is engaged with the guided member 21 and is provided so that the upper surface (guide surface) of the guide portion 20 and the inner surface of the guided member 21 face each other. A gas bearing (air bearing), which is a non-contact bearing, is provided on the guide surface of the guide portion 20, and the X guide stage 17 is supported in a non-contact manner with respect to the guide surface.

  The liquid supply mechanism SW supplies the liquid Lq between the projection optical system PL and the wafer W, and includes an ultrapure water production apparatus 30, a temperature adjustment apparatus 31, and a supply nozzle 32. The ultrapure water production apparatus 30 is an apparatus that produces ultrapure water with high purity. The temperature control device 31 includes a temperature control unit that controls the temperature of the ultrapure water produced by the ultrapure water production device 30 at a constant level, a deaeration unit that degass the ultrapure water, and temperature control and deaerated ultrapure water And a pressure pump for delivering ultrapure water. The supply nozzle 32 is disposed close to the surface of the wafer W and is connected to the temperature adjustment device 31 via the supply pipe 33, and the ultrapure water delivered from the temperature adjustment device 31 is projected as the liquid Lq. It is supplied between the optical system PL and the wafer W.

  In the middle of the supply pipe 33, a flow meter 34 for measuring the amount of liquid Lq (liquid supply amount per unit time) supplied from the temperature adjustment device 31 onto the wafer W is provided. The flow meter 34 monitors the amount of the liquid Lq supplied onto the wafer W and outputs the measurement result to the main control system MC. The main control system MC controls the liquid supply operation of the temperature control device 31 according to the monitoring result of the flow meter 34, and controls the supply amount of the liquid Lq per unit time supplied between the projection optical system PL and the wafer W. To do. A valve 35 that opens and closes the flow path of the supply pipe 33 is provided between the flow meter 34 and the supply nozzle 32 in the supply pipe 33. The opening / closing operation of the valve 35 is controlled by the main control system MC.

  The liquid recovery mechanism CW recovers the liquid Lq on the wafer W (or the substrate holder 9) supplied by the liquid supply mechanism SW, and includes a recovery nozzle 35, a vacuum system 36, a flow meter 37, and a recovery tank. 38 etc. are comprised. The recovery nozzle 35 is disposed close to the surface of the wafer W and is connected to a recovery tank 38 via a recovery tube 39. The vacuum system 36 includes a vacuum pump, and its operation is controlled by the main control system MC. When the vacuum system 36 is driven, the liquid Lq on the wafer W is recovered through the recovery nozzle 35.

  The liquid Lq recovered by the recovery nozzle 35 is guided to the recovery tank 38 via the recovery pipe 39. In the middle of the recovery pipe 39, a flow meter 37 for measuring the amount of the recovered liquid Lq (liquid recovery amount per unit time) is provided. The flow meter 37 monitors the amount of the liquid Lq collected from the wafer W through the collection nozzle 35, and outputs the measurement result to the main control system MC. The main control system MC controls the operation of the vacuum system 36 according to the monitoring result of the flow meter 37, and controls the recovery amount per unit time of the liquid Lq recovered from between the projection optical system PL and the wafer W.

  The recovery tank 38 temporarily stores the liquid Lq recovered via the recovery nozzle 35, and a discharge pipe for discharging the stored liquid Lq is provided at the bottom of the recovery tank 38. The liquid Lq discharged from the discharge pipe is discarded or cleaned, for example, and returned to the ultrapure water production apparatus 30 or the like for reuse.

  Here, the configuration of the liquid supply mechanism SW and the liquid recovery mechanism CW will be described in detail. FIG. 4 is a plan view showing an example of the positional relationship between the liquid supply mechanism SW and the liquid recovery mechanism CW and the projection region PR of the projection optical system PL. As shown in FIG. 4, the projection area PR of the projection optical system PL has a rectangular shape (slit shape) elongated in the X direction, and three supply nozzles 32a on the + Y side so as to sandwich the projection area PR in the Y direction. To 32c are arranged, and two recovery nozzles 35a and 35b are arranged on the -Y side. The supply nozzles 32 a to 32 c are connected to the temperature control device 31 via the supply pipe 33, and the recovery nozzles 35 a and 35 b are connected to the flow meter 37 via the recovery pipe 39.

  Further, supply nozzles 32a 'to 32c' are arranged at positions symmetrical to the supply nozzles 32a to 32c with respect to the projection area PR, and collection nozzles 35a 'and 35b' are arranged at positions symmetrical to the collection nozzles 35a and 35b with respect to the projection area PR. Has been. The supply nozzles 32a to 32c and the recovery nozzles 35a 'and 35b' are alternately arranged in the X direction, and the supply nozzles 32a 'to 32c' and the recovery nozzles 35a and 35b are alternately arranged in the X direction. The supply nozzles 32 a ′ to 32 c ′ are connected to the temperature control device 31 via a supply pipe 33 ′, and the recovery nozzles 35 a ′ and 35 b ′ are connected to a flow meter 37 via a recovery pipe 39. In the middle of the supply pipe 33 ′, a flow meter 34 ′ is provided in the same manner as the supply pipe 33.

  Although not shown in FIG. 1, the exposure apparatus EX includes a focus detection system that detects the position of the surface of the wafer W supported by the wafer stage WST. The focus detection system includes a light projecting unit that projects a detection light beam on the wafer W via the liquid Lq from an oblique direction, and a light receiving unit that receives the reflected light of the detection light beam reflected by the wafer W. . The light reception result of the focus detection system (light receiving unit) is output to the main control system MC. The main control system MC can detect the position information of the surface of the wafer W in the Z-axis direction and the tilt information of the wafer W in the θX and θY directions based on the detection result of the focus detection system. As the configuration of the focus detection system, for example, the one disclosed in JP-A-8-37147 can be applied.

  Further, the exposure apparatus EX includes an off-axis alignment sensor on the side of the projection optical system PL. This alignment sensor is an FIA (Field Image Alignment) type alignment sensor, and is obtained from a wafer W by irradiating a mark formed on the wafer W with a broadband light beam emitted from a halogen lamp as a detection beam, for example. The reflected light is imaged by an image sensor such as a CCD (Charge Coupled Device), and the captured image signal is supplied to the main control system MC. The main control system MC performs image processing on the image signal and calculates position information of the captured mark. As this alignment sensor, for example, one disclosed in JP-A-4-65603 can be applied.

  As shown in the partial sectional view of FIG. 1, the liquid supply mechanism SW and the liquid recovery mechanism CW are separated and supported with respect to the lens barrel surface plate 7. Thereby, the vibration generated by the liquid supply mechanism SW and the liquid recovery mechanism CW is not transmitted to the projection optical system PL via the lens barrel surface plate 7.

  Next, an exposure method for transferring the pattern of the reticle R onto the wafer W using the exposure apparatus EX configured as described above will be described. FIG. 5 is a flowchart showing an exposure method according to the first embodiment of the present invention. When the exposure sequence is started, wafer W is loaded onto wafer stage WST (step S11). In addition, while loading the wafer W, the reticle R is also replaced if necessary.

  Next, EGA (enhanced global alignment) measurement is performed (step S12). Here, the EGA measurement is the positional information of marks (alignment marks) formed on each of the typical partial (3 to 9) shot areas preset on the wafer W, An arithmetic method for determining the regularity of the arrangement of all shot areas set on the wafer W based on the design information by a statistical method. Specifically, position information of several representative marks formed on the wafer W loaded on the wafer stage WST is measured using the alignment sensor, and the main control system MC performs EGA calculation based on the measurement result. And the regularity of the arrangement of all shot areas set on the wafer W is determined.

  Next, the main control system MC outputs a control signal to the temperature control device 31 provided in the liquid supply mechanism SW to make the temperature of the ultrapure water produced by the ultrapure water production device 30 constant, Ultrapure water with a constant temperature is delivered at a predetermined rate per unit time. The ultrapure water delivered from the temperature control device 31 is provided at the tip of the projection optical system PL via the supply pipe 33 (33 ′) and the supply nozzle 32 (32a to 32c, 32a ′ to 32c ′). 1 and the wafer W are supplied as the liquid Lq.

  The main control system MC drives the vacuum system 38 of the liquid recovery mechanism CW in accordance with the supply of the liquid Lq by the liquid supply mechanism SW, the recovery nozzle 35 (35a, 35b, 35a ′, 35b ′), and the recovery pipe 39. A predetermined amount of liquid Lq per unit time is recovered in the recovery tank 38 via Thereby, an immersion region WR of the liquid Lq is formed between the optical element 1 at the tip of the projection optical system PL and the wafer W (step S13). Here, in order to form the liquid immersion region WR, the main control system MC sets the liquid supply mechanism SW so that, for example, the liquid supply amount on the wafer W and the liquid recovery amount from the wafer W are substantially the same amount. And the liquid recovery mechanism CW.

  The main control system MC drives the wafer stage WST and moves the wafer W stepwise to the first exposure start position in a state where a constant amount of liquid Lq is constantly supplied between the projection optical system PL and the wafer W. (Step S14). Here, the wafer W as an object to be exposed will be described. FIG. 6 is a diagram illustrating an example of a plan view of the wafer W. As shown in FIG. 6, a plurality of shot areas SA1 to SAn (n is a natural number of 2 or more) are arranged on the wafer W in the X direction and the Y direction. In FIG. 6, the maximum number of shot areas in the Y direction (scanning direction) is set to 4 for simplicity of explanation. That is, the case where the maximum number of shot areas in the Y direction and the number of patterns P formed in the circumferential direction of the reticle R are set to the same number will be described as an example. When the wafer W is exposed, it is assumed that the exposure is performed in the order of the shot areas SA1 to SAn shown in FIG. For this reason, in step S14 described above, wafer stage WST is driven so that shot area SA1 is arranged in the vicinity of + Y side of projection area PR.

  When the movement of the wafer W is completed, the main control system MC outputs a control signal to the wafer stage WST to start acceleration in the −Y direction, and outputs a control signal to the reticle drive mechanism RM to output the central axis CX. The rotation of the reticle R around is started. When the wafer W is moving in the −Y direction, the main control system MC rotates the reticle R in the direction from the Y axis to the Z axis (clockwise when viewed from the −X direction to the + X direction). Let After the movement speed of the wafer W in the -Y direction and the angular speed of the reticle R become constant and synchronized, when the end of the shot area SA1 on the -Y side reaches the projection area PR, the main control system MC Exposure light EL is emitted from the illumination optical system ILS to illuminate the reticle R via the reflection optical system 40, and an image of the pattern of the reticle R is projected onto the wafer W via the projection optical system PL and the liquid Lq.

  At the time of scanning exposure, in a state where a part of the pattern image of the reticle R is projected onto the projection area PR, the pattern P of the reticle R is synchronized with the projection optical system PL moving at a speed V in the + Y direction. Thus, the wafer W moves in the −Y direction at a speed β · V (β is a projection magnification). Since the reticle R shown in FIG. 3 has four patterns P formed in the circumferential direction, exposure of the shot area SA1 is completed when the reticle R rotates 90 °. If the measurement result that the shot area on the wafer W has an arrangement error or that the shot area is deformed is obtained by the above EGA measurement, the moving speed of the wafer stage WST, the reticle R The pattern image projected on the wafer W is corrected in accordance with the shot area arrangement error or deformation by performing fine adjustment of the rotation speed of the reticle R, fine adjustment of the rotation axis of the reticle R, or adjustment of the optical characteristics of the projection optical system PL. Is desirable.

  When the scanning exposure for the shot area SA1 to be exposed first is completed, the wafer stage WST continues to move in the −Y direction without decelerating the wafer stage WST, and the rotation of the reticle R is continued. Then, the shot area SA2 arranged on the + Y side of the shot area SA1 is similarly exposed. In other words, in the present embodiment, exposure of one row of shot areas arranged in the Y direction is continuously performed by one scan (step S15).

  In the present embodiment, the liquid Lq is made to flow in the same direction as the movement direction of the wafer W. That is, when scanning exposure is performed by moving the wafer W in the scanning direction SD1 (−Y direction) in FIG. 4, the supply pipe 33, the supply nozzles 32a to 32c, the collection nozzles 35a and 35b, and the collection pipe 39 are provided. The liquid Lq is supplied and recovered by the liquid supply mechanism SW and the liquid recovery mechanism CW. That is, when the wafer W moves in the −Y direction, the liquid Lq is supplied between the projection optical system PL and the wafer W from the supply nozzle 32 (32a to 32c), and the liquid Lq on the wafer W is The liquid Lq flows in the −Y direction so as to fill the space between the optical element 1 and the wafer W at the front end of the projection optical system PL together with the surrounding gas from the collection nozzle 35 (35a, 35b).

  When exposure of shot area SA2 is completed, main control system MC decelerates wafer stage WST. Then, it is determined whether or not the exposure of one wafer W has been completed, that is, whether or not all the exposure on the wafer W has been completed (step S16). Here, since only the exposure of the shot areas SA1 and SA2 has just been completed and there are other shot areas to be exposed, the determination result in step S16 is “NO”. Next, the main control system MC outputs a control signal to the reticle drive mechanism RM to reverse the rotation direction of the reticle R (step S17). That is, the reticle R is rotated in the direction from the Z axis to the Y axis (counterclockwise when viewed from the −X direction to the + X direction). Next, main control system MC drives wafer stage WST to move wafer W stepwise to the next exposure start position (step S18). Specifically, wafer stage WST is driven so that shot area SA3 to be exposed next is positioned in the vicinity of −Y side of projection area PR. In order to improve the throughput, it is desirable to perform the reversal of the reticle rotation direction in step S17 during the movement of wafer stage WST in step S18. In addition, during the reversing operation of the rotation direction of the reticle R, it is desirable not to irradiate the reticle R with the exposure light EL (to temporarily stop the exposure of the wafer W).

  When the above movement of wafer W is completed, main control system MC sets the movement direction of wafer stage WST in the reverse direction, outputs a control signal to wafer stage WST, and starts acceleration in the + Y direction (step S19). ). Note that the reticle R is assumed to have started to rotate in the direction from the Z axis to the Y axis (counterclockwise when viewed from the −X direction to the + X direction) in the process of step S17. After the movement speed of the wafer W in the + Y direction and the angular speed of the reticle R become constant and synchronized, when the + Y side end of the shot area SA3 reaches the projection area PR, the main control system MC performs illumination optics. Exposure light EL is emitted from the system ILS to illuminate the reticle R via the reflection optical system 40, and an image of the pattern of the reticle R is projected onto the wafer W via the projection optical system PL and the liquid Lq.

  At this time, in a state in which a part of the pattern image of the reticle R is projected onto the projection region PR, the pattern P of the reticle R is synchronized with the projection optical system PL moving at the velocity V in the −Y direction. Thus, the wafer W moves in the + Y direction at a speed β · V. Then, the shot areas SA3 to SA6 arranged in the Y direction are sequentially exposed. Since the reticle R shown in FIG. 3 has four patterns P formed in the circumferential direction, exposure of the shot areas SA3 to SA6 for one row is completed when the reticle R rotates 360 °.

  When scanning exposure is performed by moving the wafer W in the + Y direction (scanning direction SD2 in FIG. 2), supply pipes 33 'supply nozzles 32a' to 32c ', recovery nozzles 35a' and 35b ', and recovery are performed. Using the tube 39, the liquid Lq is supplied and recovered by the liquid supply mechanism SW and the liquid recovery mechanism CW. That is, when the wafer W moves in the + Y direction, the liquid Lq is supplied between the projection optical system PL and the wafer W from the supply nozzle 32 '(32a' to 32c '), and the liquid on the wafer W is also supplied. The liquid Lq is recovered in the + Y direction so that Lq is recovered from the recovery nozzle 35 (35a ′, 35b ′) together with the surrounding gas so that the space between the optical element 1 at the front end of the projection optical system PL and the wafer W is filled. Flowing.

  Similarly, every time exposure of one row of shot areas arranged in the Y direction is completed, the rotation direction of the reticle R is reversed, and the moving direction (scanning direction) of the wafer stage WST is reversed so as to be in column units. In step S15 to S19, exposure processing is performed. When the above operation is repeated and the main control system MC determines that all the exposure on the wafer W has been completed (when the determination result of step S16 is “YES”), the main control system MC is on the wafer stage WST. The wafer W placed on the substrate is unloaded (step S20). Then, it is determined whether or not there is a wafer W to be exposed next (step S21). If there is a wafer W to be exposed, the determination result is “YES”, and the processes in and after step S11 are repeated. On the other hand, if there is no wafer W to be exposed, the determination result is “NO”, and the series of exposure processing ends.

  As described above, in the present embodiment, one shot area arranged in the Y direction is exposed by one scanning while rotating the cylindrical reticle R in which a plurality of patterns P are formed in the circumferential direction. ing. Each time the exposure of one row of shot areas arranged in the Y direction is completed, the rotation direction of the reticle R is reversed and the moving direction (scanning direction) of the wafer stage WST is reversed, so that a plurality of rows are obtained. The shot area is exposed. Therefore, the number of times of acceleration / deceleration of wafer stage WST can be greatly reduced as compared with the conventional case. Further, in the present embodiment, since the cylindrical reticle R on which a plurality of patterns P are formed is used, compared to a case where a plurality of patterns are formed on a planar reticle or a case where a plurality of reticle stages are provided. There is no significant cost increase of the exposure apparatus EX.

  Further, in the exposure apparatus EX of the present embodiment, the exposure is not performed while frequently changing the scanning direction of the wafer stage WST for each shot area as in the prior art, and scanning is performed without changing the scanning direction of the wafer stage WST. One row of shot areas arranged in the direction (Y direction) is continuously exposed. Therefore, the immersion area WR between the optical element 1 of the projection optical system PL and the wafer W can be stabilized, and the exposure accuracy can be improved. Further, for example, when the scanning direction is frequently changed, there is a possibility that bubbles may enter the liquid immersion region WR and cause a defect. However, in this embodiment, the number of times the scanning direction is changed is larger than that in the past. Because it is far less, the probability of such defects can be greatly reduced.

  In the above embodiment, the case where exposure is performed using the reticle R in which a plurality of patterns P are formed in the circumferential direction is described as an example. However, one pattern is formed in the circumferential direction of the reticle R. Only it is good. FIG. 7 is a development view showing another example of the reticle R used in the first embodiment of the present invention. In the example shown in FIG. 7, one pattern forming area PA ′ is provided along the circumferential direction of the reticle R, and one pattern P ′ to be transferred onto the wafer W is formed inside the pattern forming area PA ′. Has been.

  This pattern P ′ is obtained by patterning a metal film made of, for example, chromium (Cr) into a predetermined shape, and its planar shape is a shape obtained by extending a pattern to be transferred to a shot area on the wafer W in the circumferential direction. is there. Here, in order to increase the radius of curvature of the reticle R, a pattern P ′ extended in the circumferential direction of the reticle R is shown, but when the radius of curvature may be small, a shot on the wafer W is shown. The shape may be similar to the pattern to be transferred to the region. When the reticle R on which such a pattern P ′ is formed is used, it is necessary to rotate the reticle R 360 ° every time one shot area is exposed. For this reason, it is necessary to quadruple the rotational speed of the reticle R compared to the case where the reticle R on which the four patterns P shown in FIG. 3B are formed is used.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. The overall configuration of the exposure apparatus of the present embodiment is substantially the same as that of the exposure apparatus EX of the first embodiment shown in FIG. 1, but the configurations of the reticle R and the reticle drive mechanism RM used are different. FIG. 8 is a view showing a reticle R used in the second embodiment of the present invention. As shown in FIG. 8A, the cylindrical reticle R can be rotated around the central axis CX in the same manner as the reticle R shown in FIG. However, the difference is that the side surface is divided into a first region Z1 and a second region Z2.

  In the first region Z1 of the reticle R, as developed and shown in FIG. 8B, a plurality of pattern formation regions PA1 are provided along the circumferential direction of the reticle R, and each of these pattern formation regions PA1 is provided. A pattern P1 to be transferred onto the wafer W is formed inside. The second region Z2 of the reticle R is provided with a plurality of pattern formation regions PA2 along the circumferential direction of the reticle R as shown in FIG. A pattern P2 to be transferred onto the wafer W is formed inside each. 8B and 8C, like FIG. 3B, the circumference of the reticle R in the direction from the Y axis toward the Z axis (clockwise when viewed from the −X direction to the + X direction). It is an expanded view when the top is viewed from the inside. Thus, the reticle R used in the present embodiment has a plurality of rows of patterns along the direction of the central axis CX.

  These patterns P1 and P2 extending over a plurality of rows are obtained by patterning, for example, a metal film made of chromium (Cr) or the like into a predetermined shape, and the planar shape thereof is similar to the pattern transferred to the shot area on the wafer W. It is. However, the pattern P1 and the pattern P2 are in a relationship of being rotated 180 ° on the periphery (on the side surface) of the reticle R. In the reticle R of this embodiment, the patterns P1 and P2 are arranged along the circumferential direction in order to increase the radius of curvature of the reticle R, increase the moment of inertia, and further reduce the number of times of acceleration / deceleration of the wafer stage WST. Are formed. In the example shown in FIGS. 8B and 8C, an example is shown in which four patterns P1 and P2 are formed in the circumferential direction of the reticle R for simplicity of illustration. It is desirable to form the maximum number of patterns P in the Y direction (scanning direction) of the shot areas arranged above.

  Similar to the first embodiment, the reticle drive mechanism RM holds the reticle R so that the central axis CX is along the X direction, and holds the reticle R so as to be rotatable around the central axis CX. However, the reticle driving mechanism RM is different in that the reticle R is rotated only in one direction (direction from the Y axis toward the Z axis (clockwise when viewed from the −X direction to the + X direction)). As in the first embodiment, the reticle R can be finely rotated around the Y axis and the Z axis (θY, θZ), and the reticle R is held exchangeably. Further, the reticle driving mechanism RM of the present embodiment can translate (shift) the reticle R along the X direction. Thereby, it is possible to irradiate only one of the first region Z1 and the second region Z2 with the exposure light EL emitted from the illumination optical system ILS and reflected by the reflection optical system 40. Here, instead of translating (shifting) the reticle R, it is also possible to provide an optical system for irradiating both the pattern P1 and the pattern P2 with the exposure light EL, and to switch optically.

  FIG. 9 is a flowchart showing an exposure method according to the second embodiment of the present invention. In FIG. 9, the same reference numerals are given to steps in which the same processing as the processing in the flowchart shown in FIG. 5 is performed. 9 and 5 is different in that step S22 is provided instead of step S17 in FIG. When the exposure sequence is started, the wafer W is loaded onto the wafer stage WST (step S11), EGA measurement is performed (step S12), and the immersion region WR is formed (step S13), as in the first embodiment. ) The wafer W is stepped to the first exposure start position (step S14). In the initial state, it is assumed that the second region Z2 of the reticle R is irradiated with the exposure light EL.

  When the movement of the wafer W is completed, the main control system MC outputs a control signal to the wafer stage WST to start acceleration in the −Y direction, and outputs a control signal to the reticle drive mechanism RM to output the central axis CX. The rotation of the reticle R around is started. Note that the reticle drive mechanism RM rotates the reticle R clockwise when the + X direction is viewed from the −X direction. After the movement speed of the wafer W in the -Y direction and the angular speed of the reticle R become constant and synchronized, when the end of the shot area SA1 on the -Y side reaches the projection area PR, the main control system MC The exposure light EL is emitted from the illumination optical system ILS. The exposure light EL is irradiated onto the second region Z2 of the reticle R via the reflection optical system 40, whereby an image of the pattern P2 formed on the reticle R is projected onto the wafer W via the projection optical system PL and the liquid Lq. Projected. As in the first embodiment, the pattern P2 is sequentially transferred to the shot area SA1.

  When the scanning exposure for the shot area SA1 to be exposed first is completed, the wafer stage WST continues to move in the −Y direction without decelerating the wafer stage WST, and the rotation of the reticle R is continued. The exposure of the shot area SA2 arranged on the + Y side of the shot area SA1 is similarly performed (step S15). When exposure of shot area SA2 is completed, main control system MC decelerates wafer stage WST. Then, it is determined whether or not the exposure of one wafer W has been completed, that is, whether or not all the exposure on the wafer W has been completed (step S16).

  If the determination result in step S16 is “NO”, the main control system MC outputs a control signal to the reticle drive mechanism RM to shift the reticle R in the + X direction (step S22). At this time, the rotation direction of the reticle R is not reversed as in the first embodiment. Next, main control system MC drives wafer stage WST to move wafer W stepwise to the next exposure start position (step S18). Specifically, wafer stage WST is driven so that shot area SA3 to be exposed next is positioned in the vicinity of −Y side of projection area PR. In order to improve the throughput, it is desirable to shift the reticle in step S22 while moving the wafer stage WST in step S18. Further, during the shift of the reticle R, it is desirable to prevent the exposure light EL from being emitted to the reticle R (so that the exposure of the wafer W is temporarily stopped).

  When the above movement of wafer W is completed, main control system MC sets the movement direction of wafer stage WST in the reverse direction, outputs a control signal to wafer stage WST, and starts acceleration in the + Y direction (step S19). ). Then, after the moving speed of the wafer W in the + Y direction and the angular speed of the reticle R become constant and synchronized, when the end on the + Y side of the shot area SA3 reaches the projection area PR, the illumination optical system ILS Exposure light EL is emitted. The exposure light EL is applied to the first region Z1 of the reticle R via the reflection optical system 40, and an image of the pattern P1 formed on the reticle R thereby on the wafer W via the projection optical system PL and the liquid Lq. Projected. Then, the pattern P1 is sequentially exposed to each of the shot areas SA3 to SA6 arranged in the Y direction.

  Similarly, every time exposure of one row of shot areas arranged in the Y direction is completed, the reticle R is shifted in the X direction, and the moving direction (scanning direction) of the wafer stage WST is reversed to form a column unit. In step S15, S16, S22, S18 to S19, the exposure process is performed. When the above operation is repeated and the main control system MC determines that all the exposure on the wafer W has been completed (when the determination result of step S16 is “YES”), the main control system MC is on the wafer stage WST. The wafer W placed on the substrate is unloaded (step S20). Then, it is determined whether or not there is a wafer W to be exposed next (step S21). If there is a wafer W to be exposed, the determination result is “YES”, and the processes in and after step S11 are repeated. On the other hand, if there is no wafer W to be exposed, the determination result is “NO”, and the series of exposure processing ends.

  As described above, in the present embodiment, the reticle R is continuously rotated in one direction, and the reticle P is shifted in the X direction according to the scanning direction of the wafer stage WST to switch the patterns P1 and P2 to be transferred. . According to this embodiment performing such an operation, as in the first embodiment, the number of times of acceleration / deceleration of wafer stage WST is reduced, a significant increase in cost of the exposure apparatus is suppressed, and exposure accuracy is improved. Can do. Furthermore, according to the present embodiment, since it is not necessary to reverse the rotation direction of the reticle R, it is possible to omit the time required until the rotation speed becomes a constant speed by reversing the rotation direction of the reticle R. Thereby, the throughput can be improved.

  In the present embodiment, as described above, the reticle R is continuously rotated in one direction regardless of the moving direction of the wafer stage WST, and the reticle R is shifted in the X direction according to the moving direction of the wafer stage WST. Different patterns (patterns that are rotated 180 ° on the periphery (side surface) of the reticle R) are transferred. For this reason, the pattern P2 formed in the second region Z2 is transferred when the pattern P2 moves in the + Y direction and the wafer W moves in the -Y direction in the lowermost part BT of the reticle R. On the other hand, the pattern P1 formed in the first region Z1 is transferred when the pattern P1 moves in the + Y direction and the wafer W moves in the + Y direction in the lowermost part BT of the reticle R.

  Here, the exposure apparatus of the present embodiment includes a projection optical system PL that projects an inverted image onto the wafer W, as in the first embodiment. Therefore, when the exposure light EL irradiated to the reticle R is slit-shaped and has a width in the Y direction, the movement direction of the pattern of the reticle R and the movement direction of the wafer W are opposite to each other. Otherwise, the pattern cannot be exposed normally. That is, when the exposure light EL has a slit shape, the pattern P2 formed in the second region Z2 can be transferred normally, but the pattern P2 formed in the first region Z1 can be transferred normally. I can't write. For this reason, it should be noted that in the present embodiment, it is necessary to irradiate the lowermost part BT of the reticle R with linear exposure light EL (exposure light with extremely narrow Y in the X direction).

  In the present embodiment, a reticle R in which a pattern extending in the circumferential direction similar to the pattern shown in FIG. 7 is formed in each of the first region Z1 and the second region Z2 can be used. However, the pattern of the first region Z1 and the pattern of the second region Z2 need to be in a relationship of being rotated 180 ° on the periphery (on the side surface) of the reticle R. Further, when the reticle R on which such a pattern P is formed is used, it is necessary to rotate the reticle R 360 ° every time one shot area is exposed. Therefore, four patterns P1 and P2 shown in FIG. 8 are formed. The rotational speed of the reticle R needs to be quadrupled compared to the case where the reticle R is used.

[Third Embodiment]
Next, a third embodiment of the present invention will be described. The exposure apparatus of this embodiment enables normal pattern transfer even in the case of irradiating the reticle R with the slit-shaped exposure light EL in the exposure apparatus according to the second embodiment described above. The overall configuration of the exposure apparatus of the present embodiment is substantially the same as that of the exposure apparatus EX of the first embodiment shown in FIG. 1, and the configuration of the reticle R and reticle drive mechanism RM used is the same as that of the second embodiment. is there. However, the configuration of the projection optical system PL is different. The projection optical system PL provided in the exposure apparatus of the present embodiment can switch the projection image between an inverted image and an erect image.

  FIG. 10 is a side view showing the configuration of the projection optical system PL provided in the exposure apparatus according to the third embodiment of the present invention. As shown in FIG. 10, the projection optical system PL of the present embodiment includes a projection lens 50, a half-wave plate 51, a polarizing beam splitter 52, an erect image forming lens 53, bending mirrors 54 and 55, an erect image forming lens 56, A polarizing beam splitter 57, a half-wave plate 58, and a projection lens 59 are included. In FIG. 10, only the reticle R and the wafer W are shown in addition to the projection optical system PL, and other components such as the supply nozzle 32 and the recovery nozzle 35 are not shown. In FIG. 10, the area indicated by the thick line at the bottom of the reticle R is an illumination area IA irradiated with the slit-shaped exposure light EL extending in the X direction, and the area indicated by the thick line on the wafer W is the exposure light. This is an exposure area EA irradiated with EL.

  The projection lens 50 converts light from the reticle R into parallel light. The half-wave plates 51 and 58 change the polarization direction of the incident light, and are configured to be rotatable around the optical axis AX. The rotation amount of the half-wave plates 51 and 58 is controlled by the main control system MC. Specifically, the main control system MC controls the amount of rotation of each of the half-wave plates 51 and 58 so that the half-wave plate 58 rotates in accordance with the rotation of the half-wave plate 51. The polarization beam splitters 52 and 57 transmit only light whose polarization direction is the Y-axis direction and reflect light whose polarization direction is the X-axis direction. The erect image forming lens 53 forms an intermediate image at the intermediate image forming point MP, and the erect image forming lens 56 converts light passing through the intermediate image forming point MP into parallel light. The projection lens 59 condenses the light transmitted through the half-wave plate 58 on the wafer W.

  In the above configuration, the exposure light EL from one point in the illumination area IA is incident on the half-wave plate 51 after being incident on the projection lens 50 and converted into parallel light. Here, when the exposure light EL passes through the half-wave plate 51, the polarization direction of the exposure light EL becomes either the X direction or the Y direction. The exposure light EL that has passed through the half-wave plate 51 enters the polarization beam splitter 52. Here, when the polarization direction of the exposure light EL passing through the half-wave plate 51 is the Y direction, the exposure light EL is transmitted through the polarization beam splitter 52, and when it is in the X axis direction, the exposure light EL. Is reflected by the polarization beam splitter 52.

  The exposure light EL that has passed through the polarization beam splitter 52 reaches the polarization beam splitter 57. As described above, since the polarization beam splitter 52 and the polarization beam splitter 57 are arranged so that the polarization directions of the transmitted light are the same, the exposure light EL incident on the polarization beam splitter 57 from the polarization beam splitter 52 is The light passes through the polarization beam splitter 57. When the exposure light EL transmitted through the polarization beam splitter 57 passes through the half-wave plate 58, its polarization direction is returned to the direction before entering the half-wave plate 51 and enters the projection lens 59. To do. The projection lens 59 is emitted from one point on the illumination area IA, refracts the exposure light EL that has passed through each optical element of the projection optical system PL, and condenses it on one point in the exposure area EA on the wafer W. Let

  On the other hand, the exposure light EL reflected by the polarization beam splitter 52 is incident on the erect image forming lens 53, refracted, bent by the bending mirror 54, and then reaches the intermediate imaging point MP. An inverted image of the pattern in the illumination area IA is formed at the intermediate image formation point MP. The exposure light EL that has passed through the intermediate image forming point is bent by the bending mirror 55 and then enters the polarization beam splitter 57 via the erect image forming lens 56. Here, since the polarization beam splitter 52 and the polarization beam splitter 57 are arranged so that the polarization directions of the reflected light are the same, the polarization beam splitter 57 receives the exposure light EL from the erect image forming lens 56. reflect. When the exposure light EL reflected by the polarization beam splitter 57 passes through the half-wave plate 58, the polarization direction is returned to the direction before entering the half-wave plate 51, and the projection light 59 is incident on the projection lens 59. Incident. The projection lens 59 is emitted from one point on the illumination area IA, refracts the exposure light EL that has passed through each optical element of the projection optical system PL, and condenses it on one point in the exposure area EA on the wafer W. Let

  By the way, in FIG. 10, the principal ray of the exposure light EL from the point Q1 on the + Y side in the illumination area IA is illustrated by a broken line or a two-dot difference line. The path of the exposure light EL differs depending on whether it is transmitted through the polarization beam splitter 52 or reflected by the polarization beam splitter 52, but the principal ray when transmitted through the polarization beam splitter 52 is indicated by a broken line. The principal ray in the case of being reflected by is shown by a two-dot difference line. As shown in FIG. 10, when passing through the polarizing beam splitter 52, the principal ray of the exposure light EL from the point Q1 reaches the point Q2 in the exposure area EA through a path indicated by a broken line. That is, in such a case, the image of the point Q1 in the illumination area IA is formed at the point Q2 in the exposure area EA. On the other hand, when reflected by the polarization beam splitter 52, the principal ray of the exposure light EL from the point Q1 reaches the point Q3 in the exposure area EA through the path indicated by the two-dot chain line. That is, in such a case, the image of the point Q1 in the illumination area IA is formed at the point Q3 in the exposure area EA.

  From the above, when viewed in the entire illumination area IA, when the exposure light EL passes through the polarization beam splitter 52, an inverted image of the pattern in the illumination area IA is formed in the exposure area EA, and the polarization beam splitter 52 is formed. When the light is reflected at the exposure area EA, an erect image of the pattern in the illumination area IA is formed on the exposure area EA. That is, whether the pattern image in the illumination area IA is an inverted image or an erect image is determined depending on whether the exposure light EL is transmitted through or reflected by the polarization beam splitter 52. Since the polarization direction of the exposure light EL in the projection optical system PL is determined by the rotation amount of the half-wave plate 51, the main control system MC adjusts the rotation amount of the half-wave plate 51, so that an inverted image is obtained. Can be projected onto the wafer W or an upright image can be projected onto the wafer W.

  Here, in the second embodiment described above, when the pattern P2 formed in the second region Z2 is transferred, the pattern P2 is moved in the + Y direction in the lowermost part BT of the reticle R, and the wafer W is moved to -Y. When the pattern P1 formed in the first region Z1 is transferred, the pattern P1 is moved in the + Y direction and the wafer W is moved in the + Y direction at the lowermost part BT of the reticle R. It was. For this reason, when transferring the pattern P1 formed in the first region Z1, an inverted image is projected on the wafer W, and when transferring the pattern P2 formed in the second region Z2, it is positive on the wafer W. If a standing image is projected, normal pattern transfer is possible in any case where the patterns P1 and P2 are transferred.

  In the present embodiment, the wafer W can be exposed using the same exposure method as in the second embodiment shown in FIG. However, for example, in step S22 shown in FIG. 9, the reticle R is shifted and the half-wave plates 51 and 58 shown in FIG. 10 are rotated so that an inverted image is projected or corrected according to the moving direction of the wafer stage WST. It is necessary to switch the projection of the standing image. As described above, in the present embodiment, similar to the second embodiment, the number of times of acceleration / deceleration of the wafer stage WST can be reduced, the throughput can be improved, and normal pattern transfer can be performed even using the slit-shaped exposure light EL. It can be carried out.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described. The overall configuration of the exposure apparatus of this embodiment is substantially the same as that of the exposure apparatus EX of the first embodiment shown in FIG. 1, but the exposure light EL from the reticle R and the illumination optical system ILS to be used is used as the reticle R. The configuration of the irradiating optical system is different. FIG. 11 is a view showing a reticle R used in the fourth embodiment of the present invention. As shown in FIG. 11A, the cylindrical reticle R can be rotated around the central axis CX in the same manner as the reticle R shown in FIG. However, as shown in FIG. 11B, the pattern portion A1 provided with the pattern formation region PA along the circumferential direction of the reticle R and the transparent portion A2 provided with no pattern formation region are provided. Is different. Here, the transparent portion A2 is a region through which the irradiated exposure light EL is transmitted.

  In the example shown in FIG. 11B, the ratio of the pattern portion A1 and the transparent portion A2 in the circumferential direction is set to 1: 1. For this reason, when the reticle R is rotated in one direction, the pattern portions A1 and the transparent portions A2 appear alternately every time the reticle R rotates 180 °. In addition, the ratio for which the pattern part A1 and the transparent part A2 occupy in the circumferential direction is not necessarily limited to 1: 1. In the example shown in FIG. 11B, two pattern formation areas PA are provided in the pattern portion A1, and a pattern P similar to the reticle R shown in FIG. In the example shown in FIG. 11B, for the sake of simplicity, an example in which two patterns P are formed in the pattern portion A1 is shown. However, the pattern portion A1 is arranged on the wafer W. It is desirable to form the maximum number of patterns P in the Y direction (scanning direction) of the shot areas. Note that the reticle driving mechanism MC can rotate the reticle R only in one direction at a constant speed, as in the second embodiment. The reticle drive mechanism MC can finely rotate the reticle R around the Y axis and the Z axis (θY, θZ).

  The exposure apparatus of the present embodiment replaces the reflective optical system 40 shown in FIG. 2 as a transmission optical system shown in FIG. 12 as an optical system that irradiates the cylindrical reticle R with the exposure light EL emitted from the illumination optical system ILS. 60. FIG. 12 is a side view showing a transmission optical system that irradiates the exposure light EL onto the cylindrical reticle R. FIG. As shown in FIG. 12, the transmission optical system 60 is arranged above the cylindrical reticle R and inside the reticle R, and includes a first cylindrical lens 61, a bending mirror 62, and a second cylindrical lens 63. Is done. In FIG. 12, the pattern portion A1 of the reticle R is indicated by a bold line, and the transparent portion A2 is indicated by a dotted line.

  The first cylindrical lens 61 corrects the shape of the slit-shaped exposure light EL emitted from the illumination optical system ILS. The folding mirror 62 is disposed above the reticle R (+ Z direction), and deflects the exposure light EL that passes through the first cylindrical lens 61 and travels in the −Y direction toward the reticle R in the −Z direction. Here, the bending mirror 62 deflects the exposure light EL toward the uppermost part TP of the cylindrical reticle R. The second cylindrical lens 63 is disposed inside the reticle R, and corrects the shape of the exposure light EL that is deflected by the bending mirror 62 and transmitted through the uppermost portion TP of the reticle R. That is, the slit-shaped exposure light EL emitted from the illumination optical system ILS is corrected by the first cylindrical lens 61 and the second cylindrical lens 63 into a linear shape extending in the X direction or a slit shape having a predetermined width. At the same time, the light passes through the uppermost part TP of the cylindrical reticle R and is irradiated to the lowermost part BT of the reticle R. In this way, the transmission optical system 60 illuminates the reticle R by transmission. Also in this embodiment, the reticle R has its lowermost part BT arranged at the focal position on the object side of the projection optical system PL.

  Next, an exposure method according to the fourth embodiment of the present invention will be described. In the following description, for the sake of simplicity, only the maximum number (here, four) of shot areas arranged on the wafer W in the Y direction (scanning direction) is included in the reticle pattern portion A1. It is assumed that a pattern P is formed. FIG. 13 is a flowchart showing an exposure method according to the fourth embodiment of the present invention. In FIG. 13, the same reference numerals are given to steps in which processing similar to the processing in the flowchart shown in FIG. 5 is performed. Comparing the flowcharts shown in FIGS. 13 and 5, the difference is that step S <b> 23 is provided instead of steps S <b> 17 and S <b> 18 in FIG. 5.

  When the exposure sequence is started, the wafer W is loaded onto the wafer stage WST (step S11), EGA measurement is performed (step S12), and the immersion region WR is formed (step S13), as in the first embodiment. ) The wafer W is stepped to the first exposure start position (step S14). When the movement of the wafer W is completed, the main control system MC outputs a control signal to the wafer stage WST to start acceleration in the −Y direction, and outputs a control signal to the reticle drive mechanism RM to output the central axis CX. The rotation of the reticle R around is started. Note that the reticle drive mechanism RM rotates the reticle R clockwise when the + X direction is viewed from the −X direction.

  After the movement speed of the wafer W in the −Y direction and the angular speed of the reticle R become constant and synchronized, the −Y side end of the shot area SA1 reaches the projection area PR, and the periphery of the pattern area A1 When one end E1 in the direction reaches the bottom BT, the main control system MC emits the exposure light EL from the illumination optical system ILS. The exposure light EL is irradiated from above the reticle R onto the top TP of the reticle by the transmission optical system 60. When one end E1 of the pattern part A1 reaches the lowermost part BT, the other end E2 of the pattern part is located at the uppermost part TP. Therefore, if the rotation proceeds as it is, the transparent part A2 is located at the uppermost part of the reticle R. The exposure light EL applied to the uppermost part TP passes through the transparent part A2, and is applied to the lowermost part BT of the reticle R from the inside of the reticle R. Thereby, the image of the pattern P formed on the reticle R is projected onto the wafer W through the projection optical system PL and the liquid Lq. As in the first embodiment, the pattern P is sequentially transferred to the shot area SA1.

  When the scanning exposure for the shot area SA1 to be exposed first is completed, the wafer stage WST continues to move in the −Y direction without decelerating the wafer stage WST, and the rotation of the reticle R is continued. The exposure of the shot area SA2 arranged on the + Y side of the shot area SA1 is similarly performed (step S15). When exposure of shot area SA2 is completed, main control system MC decelerates wafer stage WST. Then, it is determined whether or not the exposure of one wafer W has been completed, that is, whether or not all the exposure on the wafer W has been completed (step S16).

  If the determination result in this step S16 is “NO”, the main control system MC drives the wafer stage WST to step the wafer W to the next exposure start position, and to move the wafer W step by step. While in operation, reticle R is rotated 180 ° (step S18). Note that the reticle R is not rotated by 180 ° during the step movement of the wafer W, but the reticle R is rotated by 180 ° until exposure of the next shot area (shot area SA3) to be exposed is started (step S23). . Here, by rotating the reticle R by 180 °, the end E1 located at the lowermost BT when the exposure of the shot area SA1 is started is again located at the lowermost BT.

  When the above step movement of wafer W is completed, main control system MC sets the movement direction of wafer stage WST in the reverse direction, outputs a control signal to wafer stage WST, and starts acceleration in the + Y direction (step) S19). After the movement speed of the wafer W in the + Y direction and the angular speed of the reticle R become constant and synchronized, the pattern of the reticle R that the + Y side end of the shot area SA3 reaches the projection area PR and continues to rotate When one end E1 in the circumferential direction of the portion A1 reaches the lowermost part BT, the main control system MC emits the exposure light EL from the illumination optical system ILS. The exposure light EL is applied to the lowermost part BT of the reticle R via the transmission optical system 60 and the transparent portion A2 of the reticle R, whereby the image of the pattern P formed on the reticle R passes through the projection optical system PL and the liquid Lq. And projected onto the wafer W. Then, the pattern P is sequentially exposed to each of the shot areas SA3 to SA6 arranged in the Y direction. In the present embodiment, when the reticle R is rotated by 180 °, the shot areas SA3 to SA6 are all exposed.

  Similarly, every time exposure of one row of shot areas arranged in the Y direction is completed, exposure processing in units of rows is performed while rotating the reticle R by 180 ° during the step movement of the wafer W. (Steps S15, S16, S23, S19). When the above operation is repeated and the main control system MC determines that all exposures on the wafer W have been completed (when the determination result in step S16 is “YES”), the main control system MC is on the wafer stage WST. Is unloaded (step S20), and it is determined whether or not there is a wafer W to be exposed next (step S21). If there is a wafer W to be exposed, the determination result is “YES”, and the processes in and after step S11 are repeated. On the other hand, if there is no wafer W to be exposed, the determination result is “NO”, and the series of exposure processing ends.

  As described above, in the present embodiment, the reticle R is continuously rotated in one direction, exposure processing is performed while the pattern portion A1 of the reticle R is illuminated at the lowermost portion BT, and the pattern portion A1 is the uppermost portion. While being disposed on the TP, the wafer W is moved stepwise. According to this embodiment performing such an operation, as in the first embodiment, the number of times of acceleration / deceleration of wafer stage WST is reduced, a significant increase in cost of exposure apparatus EX is suppressed, and exposure accuracy is improved. be able to. Furthermore, according to the present embodiment, it is not necessary to reverse the rotation direction of the reticle R, and the rotation of the reticle R can be performed while the wafer W is being moved stepwise. It is possible to save the time required for the rotation speed to be constant and the time required for rotating the reticle R by 180 °. Thereby, the throughput can be improved.

  In the fourth embodiment described above, since the reticle R provided with the pattern portion A1 and the transparent portion A2 needs to be used to transmit the exposure light EL, the pattern on the periphery of the reticle R is used. It is desirable to use an active mask that can change the formation position of the substrate. Here, in the fourth embodiment, the reticle R is rotated 180 ° each time one row of shot areas is exposed because the exposure light EL is shielded by the pattern portion A1, and the light shielding portion of the exposure light EL is blocked. If it is eliminated, it is considered that the rotation of the reticle R that is performed each time one shot region is exposed can be omitted, and the throughput can be improved.

  Therefore, if the reticle R is used as an active mask and a pattern is formed only in the lowermost part BT of the reticle R and in the vicinity thereof, for example, according to the rotation of the reticle R, the exposure light is emitted in the uppermost part TP of the reticle R and in the vicinity thereof. Since EL is not shielded from light, throughput can be improved. The active mask is generally an electronic mask. The electronic mask is a concept including both a non-light-emitting image display element such as liquid crystal or DMD (digital micromirror device) and a self-light-emitting image display element.

  Here, the non-light emitting image display element is also called a spatial light modulator, and is an element that spatially modulates the amplitude, phase, or polarization state of light. It can be divided into a reflective spatial light modulator. The transmissive spatial light modulator includes a transmissive liquid crystal display (LCD), an electrochromic display (ECD), and the like. The reflective spatial light modulator includes DMD (Digital Mirror Device or Digital Micro-mirror Device), reflective mirror array, reflective liquid crystal display element, electrophoretic display (EPD), electronic paper (or electronic ink). ), Grating Light Value, etc. are included.

Self-luminous image display elements include CRT (Cathod Ray Tube), inorganic EL (Electro Luminescence) display, field emission display (FED), plasma display (PDP), A solid light source chip having a light emitting point, a solid light source chip array in which a plurality of chips are arranged in an array, or a solid light source array in which a plurality of light emitting points are formed on a single substrate (for example, LED (Light Emitting Diode) display, OLED (Organic Light Emitting Diode) display, LD (Laser Diode) display, etc.). The well-known plasma display (PDP)
If the fluorescent material provided in each pixel is removed, a self-luminous image display element that emits light in the ultraviolet region is obtained.

[Fifth Embodiment]
Next, a fifth embodiment of the present invention will be described. In the present embodiment, a transmission optical system 70 shown in FIG. 14 is used instead of the transmission optical system 60 (an optical system that irradiates the reticle R with the exposure light EL from the illumination optical system ILS) provided in the fourth embodiment. The point to prepare is different. FIG. 14 is a side view showing the transmission optical system 70. As shown in FIG. 14, the transmission optical system 70 of the present embodiment includes a first cylindrical lens 71, a bending mirror 72, and a second cylindrical lens 73, and is substantially the same as the transmission optical system 60 shown in FIG. It is a configuration. However, the transmission optical system 70 differs from the transmission optical system 60 in the imaging relationship. Also in FIG. 14, the pattern portion A1 of the reticle R is indicated by a bold line, and the transparent portion A2 is indicated by a dotted line.

  The first cylindrical lens 71 condenses the slit-shaped exposure light EL emitted from the illumination optical system ILS and traveling in the −Y direction so as to be condensed on the uppermost portion TP of the reticle R. The first cylindrical lens 71 condenses the exposure light EL traveling in the −Y direction in FIG. 14 only in the Z direction and does not condense in the X direction. The folding mirror 72 is disposed above the reticle R (+ Z direction), and deflects the exposure light EL that passes through the first cylindrical lens 71 and proceeds in the −Y direction toward the reticle R in the −Z direction. Here, the bending mirror 72 deflects the exposure light EL toward the uppermost part TP of the cylindrical reticle R. By deflecting the exposure light EL by the bending mirror 72, the uppermost part TP of the reticle R is irradiated with the linear exposure light EL extending in the X direction.

  The second cylindrical lens 73 is disposed inside the reticle R, and optically conjugates the uppermost part TP and the lowermost part BT of the reticle R. It is assumed that the second cylindrical lens 73 forms an erect image of a pattern disposed on the uppermost part TP of the reticle R on the lowermost part BT of the reticle R. Here, also in the present embodiment, the lowermost BT of the reticle R is disposed at the focal position on the object side of the projection optical system PL. For this reason, in the present embodiment, the uppermost portion TP of the reticle R, the lowermost portion BT of the reticle, and the surface of the wafer W positioned on the image side of the projection optical system PL are in a conjugate relationship. Therefore, the slit-shaped exposure light EL emitted from the illumination optical system ILS is condensed through the first cylindrical lens 71 and the bending mirror 72 in order, and is irradiated on the uppermost portion TP of the reticle R. The exposure light EL irradiated on the uppermost portion TP of the reticle R passes through the reticle R, enters the second cylindrical lens 73, is condensed again, and is irradiated on the lowermost portion BT of the reticle R. Thus, the transmission optical system 70 illuminates the reticle R with transmission.

  In the present embodiment including the transmission optical system 70 described above, the uppermost part TP and the lowermost part BT of the reticle R are in a conjugate relationship. Therefore, not only when the pattern part A1 is arranged on the lowermost BT side, The pattern P can be transferred to the wafer W even when it is arranged on the upper TP side. In the exposure method according to the fourth embodiment described with reference to FIG. 12, every time the exposure of one row of shot areas arranged in the Y direction is completed, the reticle R is moved 180 ° during the step movement of the wafer W. It was rotated (step S23). If the time required to rotate the reticle R by 180 ° is approximately the same as or shorter than the time required for stepping the wafer W, the throughput will not be reduced even if the exposure method according to the fourth embodiment is used.

  However, if the time for moving the wafer W stepwise is extremely short compared to the time required to rotate the reticle R by 180 °, the throughput is expected to decrease. In such a case, if the transmission optical system 60 shown in FIG. 14 is used, the exposure of the next column to be exposed immediately after the exposure of one column of shot areas arranged in the Y direction is finished and the wafer W is stepped. It becomes possible to expose the shot area. That is, when the exposure of one row of shot areas arranged in the Y direction is started when one end E1 of the pattern portion A1 reaches the lowermost BT, the exposure of the shot areas arranged in that row is performed. The process ends when the other end E2 of the pattern part A1 reaches the lowermost part BT. At this time, since one end E1 of the pattern portion A1 is disposed at the uppermost portion E2, if the wafer W is immediately moved stepwise, exposure of the shot area arranged in the next column to be exposed is started. It becomes possible. According to the fifth embodiment described above, the throughput can be improved as compared with the fourth embodiment.

  Since the transmission optical system 70 described above has a conjugate relationship between the uppermost TP and the lowermost BT of the reticle R, the focal position on the reticle R side of the projection optical system PL is dynamically switched. No. However, the configuration of the transmission optical system 70 includes a first optical system that switches whether the irradiation position of the exposure light EL on the reticle R is the uppermost TP or the lowermost BT of the reticle R, and the projection optical system PL. And a second optical system for switching whether the focal position on the object side is the uppermost TP or the lowermost BT of the reticle R, and the switching is performed according to the position of the pattern on the periphery of the reticle R. May be performed.

[Sixth Embodiment]
Next, a sixth embodiment of the present invention will be described. The overall configuration of the exposure apparatus of this embodiment is substantially the same as that of the exposure apparatus EX of the first embodiment shown in FIG. 1, but the exposure light EL emitted from the illumination optical system ILS is converted into a cylindrical reticle R. As an irradiating optical system, an internal illumination optical system 80 shown in FIG. 15 is provided instead of the reflecting optical system 40 shown in FIG. FIG. 15 is a perspective view showing the internal illumination optical system 80 that irradiates the exposure light EL onto the cylindrical reticle R. FIG. As shown in FIG. 15, the internal illumination optical system 80 is disposed inside a cylindrical reticle R, and includes a bending mirror 81, a beam expander 82, and a cylindrical lens 83.

  In the present embodiment, the exposure light EL emitted from the illumination optical system ILS travels in the −X direction, and enters the inside of the reticle R from the upper bottom or lower bottom (end on the + X side) of the reticle R. The exposure light EL emitted from the illumination optical system ILS is not a slit shape as in the first to fifth embodiments, but has, for example, a circular cross-sectional shape. The bending mirror 81 deflects the exposure light EX entering the reticle R and traveling in the −X direction in the −Z direction. The beam expander 82 is disposed below (−Z direction) the folding mirror 81 and diverges the exposure light EL that is deflected by the folding mirror 81 and travels in the −Z direction in the + X direction and the −X direction. The cylindrical lens 83 is disposed below the beam expander 82, and the shape of the exposure light EL that diverges in the + X direction and the −X direction by the expander 82 is a linear line extending in the X direction or a slit having a predetermined width. To correct.

  Therefore, the exposure light EL having a circular cross section emitted from the illumination optical system ILS is deflected in the −Z direction by the bending mirror 81 and then diverged in the + X direction and the −X direction by the beam expander 82. Then, the cylindrical lens 83 corrects the shape to a linear shape extending in the X direction or a slit shape having a predetermined width, and irradiates the side surface of the reticle R from the inside of the reticle R. Thus, the internal illumination optical system 80 illuminates the reticle R from the inside. Since the above internal illumination optical system 80 may be disposed inside the reticle R, the usable reticle R needs to be hollow. In addition, the reticle R is sandwiched between the upper bottom portion and the lower bottom portion by the reticle driving mechanism RM, but the holding portions that are disposed at both ends of the reticle R and hold the upper and lower bottom portions of the reticle R must be transparent. become. This internal illumination optical system 80 can also be used in the first to fourth embodiments described above.

  As mentioned above, although embodiment of this invention was described, this invention is not restrict | limited to the said embodiment, It can change freely within the scope of the present invention. For example, in the above-described embodiment, the case where the reticle R is an active mask in which a pattern is formed on the circumference of the cylindrical member or an active mask that can change the pattern on the circumference of the cylindrical member has been described as an example. However, for example, a reticle R including a flexible pattern sheet on which a pattern is formed and a cylindrical rotating member formed of a transparent material may be used. In such a reticle R, a rotating member is fixedly arranged in the exposure apparatus EX so as to be rotatable by a reticle driving mechanism RM, and a pattern sheet is wound around the periphery of the rotating member. By exchanging the pattern sheet, the pattern to be transferred onto the wafer W can be changed.

  In the above embodiment, the case where the reticle R has a cylindrical shape (including a columnar shape) has been described as an example. However, in the present invention, the shape of the reticle R is not limited to a cylindrical shape or a columnar shape. For example, the cross-sectional shape may be an elliptical cylinder or column shape, a shape formed by joining a plurality of curved surfaces, or a conical shape. That is, the reticle R that can be used in the present invention is rotatable. In the above embodiment, an example in which the pattern of the cylindrical reticle R is transferred onto the planar wafer W has been described. However, the wafer W does not necessarily have a planar shape, and has a cylindrical shape similar to that of the reticle R. There may be used any shape such as a sphere.

  In the above embodiment, since an ArF excimer laser light source is provided as an exposure light source, pure water is used as the liquid Lq. Pure water can be easily obtained in large quantities at a semiconductor manufacturing factory or the like, and has an advantage that it does not adversely affect the photoresist, optical elements (lenses), etc. on the wafer W. In addition, pure water has no adverse effects on the environment, and since the impurity content is extremely low, it can be expected to clean the surface of the wafer W and the surface of the optical element provided on the front end surface of the projection optical system PL. In addition, since the level of pure water in the factory (pure water level) may be low, the exposure apparatus itself may have an ultrapure water purification mechanism.

  The refractive index n of pure water (water) with respect to exposure light having a wavelength of about 193 nm is said to be approximately 1.44. When ArF excimer laser light (wavelength 193 nm) is used as the light source of exposure light, on the wafer W High resolution is obtained by shortening the wavelength to 1 / n, that is, about 134 nm. Further, since the depth of focus is expanded by about n times, that is, about 1.44 times compared with that in the air, the projection optical system PL can be used when it is sufficient to ensure the same depth of focus as that used in the air. The numerical aperture can be further increased, and the resolution is improved in this respect as well.

Note that a KrF excimer laser light source or an F ₂ laser light source can also be used as the light source 1 used for immersion exposure. When the F ₂ laser light source is used, the liquid for immersion exposure may be a fluorine-based liquid such as fluorine-based oil or perfluorinated polyether (PFPE) that can transmit the F ₂ laser light. In addition, it is also possible to use a material (for example, cedar oil) that is transparent to the exposure light, has a refractive index as high as possible, and is stable to the photoresist applied to the projection optical system PL and the surface of the wafer W. Is possible.

  In the above-described embodiment, an immersion exposure apparatus that locally fills the space between the projection optical system PL and the wafer W with a liquid is employed. However, as disclosed in JP-A-6-124873. An immersion exposure apparatus for moving a stage holding a substrate to be exposed in a liquid tank, or a liquid tank having a predetermined depth on a stage as disclosed in JP-A-10-303114, The present invention can also be applied to an immersion exposure apparatus that holds a substrate therein. The present invention is not limited to an immersion exposure apparatus, and can be applied to an exposure apparatus that does not use an immersion method.

  Further, the present invention separately mounts a substrate to be processed such as a wafer as disclosed in JP-A-10-163099, JP-A-10-214783, JP-T 2000-505958, and the like. The present invention can also be applied to a twin stage type exposure apparatus having two stages that can move independently in the XY directions.

  In the above embodiment, the step-and-scan type exposure apparatus has been described as an example. However, the present invention can also be applied to a step-and-repeat type exposure apparatus. Furthermore, the present invention is not limited to an exposure apparatus used for manufacturing a semiconductor element, but also used for manufacturing a display including a liquid crystal display element (LCD) and the like. An exposure apparatus for transferring a device pattern onto a glass plate, and a thin film magnetic head. The present invention can also be applied to an exposure apparatus that is used for manufacturing and transfers a device pattern onto a ceramic wafer, and an exposure apparatus that is used to manufacture an image sensor such as a CCD.

  Next, an embodiment of a method of manufacturing a micro device using the exposure apparatus according to the embodiment of the present invention in a lithography process will be described. FIG. 16 is a flowchart showing an example of a manufacturing process of a microdevice (a semiconductor chip such as an IC or LSI, a liquid crystal panel, a CCD, a thin film magnetic head, a micromachine, etc.). As shown in FIG. 16, first, in step S31 (design step), a function / performance design of a micro device (for example, circuit design of a semiconductor device) is performed, and a pattern design for realizing the function is performed. Subsequently, in step S32 (mask manufacturing step), a mask (reticle) on which the designed circuit pattern is formed is manufactured. On the other hand, in step S33 (wafer manufacturing step), a wafer is manufactured using a material such as silicon.

  Next, in step S34 (wafer processing step), using the mask and wafer prepared in steps S31 to S33, an actual circuit or the like is formed on the wafer by lithography or the like, as will be described later. Next, in step S35 (device assembly step), device assembly is performed using the wafer processed in step S34. Step S35 includes processes such as a dicing process, a bonding process, and a packaging process (chip encapsulation) as necessary. Finally, in step S36 (inspection step), inspections such as an operation confirmation test and a durability test of the microdevice manufactured in step S35 are performed. After these steps, the microdevice is completed and shipped.

  FIG. 17 is a diagram showing an example of a detailed flow of step S34 of FIG. 16 in the case of a semiconductor device. In FIG. 17, in step S41 (oxidation step), the surface of the wafer is oxidized. In step S42 (CVD step), an insulating film is formed on the wafer surface. In step S43 (electrode formation step), an electrode is formed on the wafer by vapor deposition. In step S44 (ion implantation step), ions are implanted into the wafer. Each of the above steps S41 to S44 constitutes a pre-processing process at each stage of the wafer processing, and is selected and executed according to a necessary process at each stage.

  At each stage of the wafer process, when the above-described pre-processing step is completed, the post-processing step is executed as follows. In this post-processing step, first, in step S45 (resist formation step), a photosensitive agent is applied to the wafer. Subsequently, in step S46 (exposure step), the circuit pattern of the mask is transferred to the wafer by the lithography system (exposure apparatus) and the exposure method described above. Next, in step S47 (development step), the exposed wafer is developed, and in step S48 (etching step), exposed members other than the portion where the resist remains are removed by etching. In step S49 (resist removal step), the resist that has become unnecessary after the etching is removed. By repeatedly performing these pre-processing steps and post-processing steps, multiple circuit patterns are formed on the wafer.

1 is a front view showing a schematic configuration of an exposure apparatus according to a first embodiment of the present invention. It is a side view which shows the reflective optical system which irradiates exposure light EL to the cylindrical reticle R. It is a figure which shows the reticle R used by 1st Embodiment of this invention. It is a top view which shows an example of positional relationship with liquid projection mechanism PR of liquid supply mechanism SW and liquid collection | recovery mechanism CW, and projection optical system PL. It is a flowchart which shows the exposure method by 1st Embodiment of this invention. 2 is a diagram illustrating an example of a plan view of a wafer W. FIG. It is an expanded view which shows the other example of the reticle R used in 1st Embodiment of this invention. It is a figure which shows the reticle R used by 2nd Embodiment of this invention. It is a flowchart which shows the exposure method by 2nd Embodiment of this invention. It is a side view which shows the structure of projection optical system PL with which the exposure apparatus by 3rd Embodiment of this invention is provided. It is a figure which shows the reticle R used by 4th Embodiment of this invention. It is a side view showing a transmission optical system for irradiating exposure light EL to a cylindrical reticle R. It is a flowchart which shows the exposure method by 4th Embodiment of this invention. 3 is a side view showing a transmission optical system 70. FIG. FIG. 6 is a perspective view showing an internal illumination optical system 80 that irradiates a cylindrical reticle R with exposure light EL. It is a flowchart which shows an example of the manufacturing process of a microdevice. It is a figure which shows an example of the detailed flow of FIG.16 S34 in the case of a semiconductor device.

Explanation of symbols

40 reflection optical system 60, 70 transmission optical system 80 internal illumination optical system A2 transparent portion CX central axis EX exposure apparatus MC main control system P, P ', P1, P2 pattern PL projection optical system R reticle SA1-SAn shot area W wafer WST wafer stage

Claims (38)

In an exposure apparatus that exposes and transfers a predetermined pattern to an object to be exposed,
A rotatable mask having a pattern to be transferred to the object to be exposed;
A stage device capable of holding and moving the object to be exposed;
An exposure apparatus comprising: a control device that synchronously controls rotation of the mask and movement of the stage device.   The exposure apparatus according to claim 1, wherein the mask has one of a cylindrical shape and a columnar shape, and is rotatable around a central axis thereof.   The exposure apparatus according to claim 2, wherein the mask is replaceable.   The exposure apparatus according to claim 2, wherein the mask is an electronic mask in which the pattern is variable.   3. An exposure apparatus according to claim 2, wherein the rotation of the mask is constant or the rotation speed can be changed between the patterns.   4. The exposure apparatus according to claim 2, wherein a plurality of the patterns are arranged along the circumferential direction on the mask. On the object to be exposed, a plurality of partitioned areas that are units for exposing and transferring the pattern are arranged,
7. The exposure apparatus according to claim 6, wherein the mask has the maximum number of patterns arranged in the circumferential direction included in one row of the partitioned areas arranged on the object to be exposed. .   4. The exposure apparatus according to claim 2, wherein the mask has a pattern in which a pattern to be transferred to the object to be exposed is extended in the circumferential direction.   The exposure apparatus according to any one of claims 6 to 8, wherein the mask has a plurality of rows of the patterns along the circumferential direction along the direction of the central axis.   The pattern included in the first column along the direction of the central axis is a pattern obtained by rotating the pattern included in the second column different from the first column by 180 ° on the circumference of the mask. An exposure apparatus according to claim 9.   11. The exposure apparatus according to claim 6, wherein the mask has a transparent portion in which the pattern is not formed in a part of the circumferential direction. 11.   11. The illumination optical system according to claim 2, further comprising an illumination optical system that irradiates the mask with exposure light extending in a direction along the central axis of the mask to reflect and illuminate the mask. The exposure apparatus described.   12. An illumination optical system that irradiates the pattern with exposure light extending in a direction along the central axis of the mask through the transparent portion of the mask and illuminates and transmits the mask. Exposure device.   3. An illumination optical system that is disposed inside the cylindrical mask and irradiates the pattern with exposure light extending in a direction along the central axis of the mask from the inside of the mask. The exposure apparatus according to claim 10.   The exposure apparatus according to any one of claims 2 to 8, wherein the control device performs control to reverse the rotation direction of the mask in accordance with a moving direction of the stage device.   The control device performs switching control of the rotation direction of the mask a plurality of times while transferring the pattern of the mask onto a plurality of partition regions on the object to be exposed. The exposure apparatus according to any one of the above.   11. The control apparatus performs control for exposing all of the partitioned areas set on the object to be exposed while rotating the mask in one direction regardless of the moving direction of the stage apparatus. The exposure apparatus described.   The control device moves the mask in a direction along the central axis according to the moving direction of the stage device, and uses the pattern included in the first row for exposure, or is included in the second row. 18. The exposure apparatus according to claim 17, wherein control is performed to switch whether to use the pattern to be used for exposure.   The exposure apparatus according to claim 4, wherein the control device performs control to switch a pattern of the electronic mask in accordance with a moving direction of the stage device. A projection optical system that is disposed between the mask and the stage device and projects an image of a pattern formed on the mask onto the object to be exposed on the stage device;
The exposure apparatus according to claim 11, further comprising: an optical system that adjusts the focus on the mask side of the projection optical system to a different position on the circumference of the mask according to an amount of rotation of the mask. In an exposure method for exposing and transferring a predetermined pattern to an object to be exposed,
An exposure method comprising: transferring a pattern of the mask to the object to be exposed while rotating a rotatable mask having a pattern to be transferred to the object to be exposed in synchronization with the movement of the object to be exposed.   22. The exposure method according to claim 21, wherein the mask has one of a cylindrical shape and a columnar shape, and is rotatable around a central axis thereof.   The exposure method according to claim 21, wherein the mask is an electronic mask in which the pattern is variable.   The exposure method according to claim 21, wherein the rotation of the mask is constant or the rotation speed can be changed between the patterns.   23. The exposure method according to claim 22, wherein the rotation direction of the mask is reversed according to the moving direction of the object to be exposed. The mask has two types of patterns rotated by 180 ° on the circumference of the mask,
23. The exposure according to claim 22, wherein which pattern is used for exposure is switched according to the moving direction of the stage apparatus while rotating the mask in one direction regardless of the moving direction of the object to be exposed. Method. The mask has a pattern forming portion in which the pattern is formed along a circumferential direction and a transparent portion in which the pattern is not formed,
The pattern is transferred to the object to be exposed while changing the position of the focus on the mask side of the projection optical system that projects the image of the mask pattern onto the object to be exposed according to the position of the pattern forming unit. 23. The exposure method according to claim 22, wherein   The whole of the divided areas included in one row of the divided areas arranged on the object to be exposed is exposed without changing the moving direction of the object to be exposed. 28. The exposure method according to any one of 27.   24. The exposure method according to claim 23, wherein the pattern of the electronic mask is switched according to the moving direction of the stage apparatus. A photoexposure mask used to transfer a predetermined pattern onto an object to be exposed,
An optical exposure mask having a pattern to be transferred to the object to be exposed and having a cylindrical shape or a cylindrical shape.   31. The photoexposure mask according to claim 30, wherein the photoexposure mask is rotatable about its central axis.   32. The photoexposure mask according to claim 30, wherein a plurality of the patterns are arranged along a circumferential direction.   33. The light exposure mask according to claim 32, wherein the pattern is arranged along the circumferential direction by the maximum number included in one row of the partitioned areas arranged on the object to be exposed.   32. The photoexposure mask according to claim 30 or 31, further comprising a pattern in which a pattern to be transferred to the object to be exposed is extended in a circumferential direction.   35. The photoexposure mask according to claim 32, wherein the pattern along the circumferential direction has a plurality of rows along the direction of the central axis.   The pattern included in the first column along the direction of the central axis is a pattern obtained by rotating the pattern included in the second column different from the first column by 180 ° on the circumference of the mask. 36. The mask for light exposure according to claim 35.   37. The photoexposure mask according to any one of claims 32 to 36, further comprising a transparent portion in which the pattern is not formed in a part of the circumferential direction. 32. The light exposure mask according to claim 30, wherein the mask is an electronic mask in which the pattern is variable.

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