JP2013021264A - Illumination device, illumination method, exposure device, and manufacturing method of electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illumination device, an illumination method, and an exposure device, capable of improving illuminance uniformity of illumination light, and to provide a manufacturing method of an electronic device.SOLUTION: An illumination device 1A, comprising: a light incident end face 20in; a rod integrator equipped with a light emission end face 20out; and a light introduction part 10A through which a plurality of light fluxes are incident on the light incident end face 20in, uses light emitted from the light emission end face 20out for an illumination light. The light introduction part 10A is so set that a plurality of light fluxes LB2 are incident at a position along a longer direction of the light incident end face 20in so that a center of the longer direction becomes a center of symmetry.

Description

  The present invention relates to an illumination technique, an exposure technique for irradiating an illumination target with illumination light via a rod integrator, and a technique for manufacturing an electronic device using the exposure technique.

  In a photolithography technique used when manufacturing a semiconductor element, a liquid crystal display element or the like, a pattern formed on a mask (reticle or photomask) is projected onto a substrate coated with a photosensitive material such as a resist, and the substrate In order to form a fine pattern thereon, it is required to illuminate the mask with substantially uniform illuminance (see, for example, Patent Document 1).

JP 2004-289123 A

  In such a photolithography technique, as the pattern formed on the substrate is further miniaturized or increased in accuracy, the tolerance of the line width error is reduced and the exposure amount is strictly controlled. It is necessary to improve the illuminance uniformity.

  In view of the above, an object of an aspect of the present invention is to provide an illumination device, an illumination method, an exposure device, and an electronic device manufacturing method that can improve the illuminance uniformity of illumination light.

  According to an aspect of the present invention, a light incident end surface, a light emitting end surface, and first and second side surfaces facing each other, and light incident from the light incident end surface is the first and second side surfaces. And a rod integrator that emits light from the light exit end face and irradiates illumination light through the rod integrator to an illumination target, from a plurality of incident positions on the light entrance end face. A light introducing portion for allowing the illumination light to enter the rod integrator, wherein the light introducing portion is a central position between the first side surface and the second side surface along a direction in which the first and second side surfaces oppose each other; There is provided an illuminating device that causes the illumination light to be incident on the rod integrator from the plurality of incident positions that are set to be symmetrical to each other.

  According to an aspect of the present invention, the light incident end surface, the light emitting end surface, and the first and second side surfaces facing each other, the light incident from the light incident end surface is the first and first An illumination method for irradiating an illumination object with illumination light via a rod integrator that reflects on two side surfaces and emits light from the light emitting end surface, wherein the first and second side surfaces face each other. Provided is an illumination method in which the illumination light is incident on the rod integrator from a plurality of incident positions on the light incident end surface set in a symmetrical arrangement with respect to a central position between one side surface and the second side surface. The

  According to another aspect of the present invention, there is provided an exposure apparatus that exposes a photosensitive substrate with light through a pattern formed on a mask, the exposure apparatus including the illumination apparatus according to the above-described aspect of the present invention. Is provided.

  Moreover, according to one aspect of the present invention, using the exposure apparatus according to one aspect of the present invention, the step of transferring the pattern to the photosensitive substrate, and the photosensitive substrate having the pattern transferred thereon, And a method for manufacturing the electronic device.

  ADVANTAGE OF THE INVENTION According to the aspect of this invention, the illuminating device which can improve the illumination intensity uniformity of illumination light, the illuminating method, the exposure apparatus, and the manufacturing method of an electronic device can be provided.

FIG. 1 is a perspective view showing an outline of an exposure apparatus according to the first embodiment of the present invention. FIG. 2 is an elevation view showing a partial configuration of the illumination optical system and the projection optical apparatus used in the exposure apparatus according to the first embodiment. FIG. 3 is a plan view showing a configuration of a mask used in the exposure apparatus according to the first embodiment. FIG. 4 is a plan view showing a relationship between a field of view by a part of the illumination optical system of the exposure apparatus according to the first embodiment and an image field by a part of the projection optical apparatus. FIG. 5 is a configuration diagram illustrating an outline of the illumination device according to the first embodiment. FIG. 6 is a perspective view illustrating a positional relationship between the light introducing unit and the rod integrator in the illumination device according to the first embodiment. FIG. 7 is a plan view of a rod integrator used in the lighting apparatus according to the first embodiment. FIG. 8 is a diagram showing the action and effect of the light beam incident on the rod integrator. FIG. 9 shows the position (coordinates) in the width direction (longitudinal direction) at the light emitting end face when a light beam having a Gaussian distribution of NA = 0.20 is incident on the rod integrator made of quartz from the center of the light incident end face. It is a figure which shows the relationship with the emitted light quantity. FIG. 10 is a graph showing the relationship between the index L × NA (n × w) indicating the performance of the rod integrator and the amount of emitted light, and plotting the amount of emitted light at the extreme end of the light emitting end surface of the rod integrator. FIG. 11 is a diagram illustrating the relationship with the amount of emitted light when the position where the light beam is incident on the light incident end face of the rod integrator is shifted. FIG. 12 is a diagram illustrating the relationship with the amount of emitted light when the distance from the center of the light incident end face of the rod integrator is different. FIG. 13 is a diagram showing the amount of light emitted from the light exit end face of the rod integrator when a light beam is vertically incident with a deviation of d1 and d2 from the central axis of the rod integrator. FIG. 14 is an explanatory diagram showing a case where three light beams are put into the light incident end face of the rod integrator. FIG. 15 is an explanatory diagram showing a case where four light beams are put into the light incident end face of the rod integrator. FIG. 16 shows emission under the condition that the illuminance is uniform when two light beams are incident on the light incident end face of the rod integrator, when the light beam interval is narrowed, and when the light beam interval is widened. It is a figure which shows distribution of light quantity. FIG. 17 is a plan view showing an incident position at which four 2 × 2 rows of light beams are incident on the light incident end face of the rod integrator in the illumination apparatus according to the second embodiment of the present invention. FIG. 18 is a perspective view showing a light introducing portion and a rod integrator in the lighting apparatus according to the second embodiment. FIG. 19 is a plan view of the illumination device according to the second embodiment. FIG. 20 is a configuration diagram showing an outline of an illumination apparatus according to the third embodiment of the present invention. FIG. 21 is a configuration diagram showing an outline of an illumination apparatus according to the fourth embodiment of the present invention. FIG. 22 is a diagram showing an emitted light quantity distribution on the light exit end face 20 when light having a Gaussian distribution of the aperture light flux 0.3 is incident on the center of the light entrance end face of the rod integrator. FIG. 23 is a diagram in which the emission angle direction of light emitted from the light emission end face is plotted along the coordinates in the width direction of the light emission end face. FIG. 24 shows a case where two light beams are vertically incident on the light incident end face so that the incident position is separated by half the longitudinal width of the light incident end face of the rod integrator and the center of the light incident end face is the center of symmetry. It is a figure which shows illuminance distribution. FIG. 25 is a diagram illustrating a result of calculating the emission angle azimuth according to the longitudinal coordinate on the light emission end face. FIG. 26 shows the emission angle azimuth along the longitudinal coordinates on the light emission end face when the incident angle of the two incident light beams remains unchanged and the incident angle is directed inward (inward so that the light beams come close to each other). FIG. FIG. 27 is a diagram showing the relationship between the emission angle azimuth and the inclination of the incident light beam at a point separated from the center of the light emission end face by ¼ of the width of the rod integrator. FIG. 28 is a diagram showing a path of light emitted from a point separated from the center of the light emitting end face by a quarter of the width of the rod integrator. FIG. 29 is a diagram showing the illuminance (the amount of emitted light) when the angle azimuth of the emitted light beam at the point y in FIG. 28 on the light emitting end face is close to perpendicular to the light emitting end face of the rod integrator. FIG. 30 is a flowchart showing a method for manufacturing a liquid crystal display element as an example of a method for manufacturing an electronic device using the exposure apparatus according to the first embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The drawings include schematic ones, and include portions having different dimensional relationships and ratios between the drawings.

[First Embodiment]
1 to 7 are views relating to an exposure apparatus according to the first embodiment of the present invention.
[Exposure equipment]
In FIG. 1, an exposure apparatus 100 is a step-and-scan scanning projection exposure apparatus, and holds an illumination unit IU that illuminates a mask M (illumination target) on which a pattern is formed, and a mask M. Holding the plate P, a mask stage (not shown) that moves, a projection optical apparatus PL that includes a plurality of projection optical systems PL1 to PL7 that project an enlarged image of the pattern of the mask M onto the plate P (exposure target), and the plate P A moving plate stage (not shown), a driving mechanism (not shown) including a linear motor and the like for driving the mask stage and the plate stage, and a main control system (not shown) for comprehensively controlling the operation of the driving mechanism and the like And.

  In the exposure apparatus 100, a mask M is sucked and held on a mask stage via a mask holder (not shown), and the position of the mask stage is measured by a laser interferometer on the mask side. Further, the plate P is sucked and held on a plate stage including a movable mirror 150 via a plate holder, and the position of the plate stage is measured by the laser interferometer on the plate side via the movable mirror 150. Based on the measurement values of the mask-side and plate-side laser interferometers, the main control system (not shown) positions, postures, speeds, and the like of the mask stage (mask M) and plate stage (plate P) via a drive mechanism. To control.

  As an example, the plate P of the present embodiment has a 1.9 × 2.2 m square, 2.2 × 2.4 m square, and 2 × 2.4 m square coated with a photoresist (photosensitive material) for manufacturing a liquid crystal display panel (electronic device). .4 × 2.8m square or 2.8 × 3.2m square rectangular plate-like glass plate, and another example is a glass plate having a side length or diagonal length greater than 500 mm. is there. As the plate P, a ceramic substrate for manufacturing a thin film magnetic head, a circular semiconductor wafer for manufacturing a semiconductor element, or the like is also applicable.

  In the description of the exposure apparatus 100, the positional relationship of each member will be described with reference to the XYZ orthogonal coordinate system set in FIG. This XYZ orthogonal coordinate system is set so that the X axis and the Y axis are parallel to the plate P, and the Z axis is set in a direction orthogonal to the plate P. In the XYZ coordinate system in FIG. 1, for example, the XY plane is set parallel to the horizontal plane and the Z axis is set in the vertical direction. In this embodiment, the direction in which the mask M and the plate P are moved synchronously (scanning direction) is set in the X direction.

  The illumination unit IU includes seven partial illumination optical systems IL1, IL2, IL3, IL4, IL5, IL6, and IL7, and is configured to partially illuminate the mask M via each of the partial illumination optical systems IL1 to IL7. The corresponding illumination areas on the mask M are illuminated uniformly. Each of the partial illumination optical systems IL1 to IL7 includes a light source unit LS that emits laser light as illumination light, a rod integrator 20, a light introduction unit 10A that guides illumination light emitted from the light source unit LS to the rod integrator 20, and a rod. A relay optical system 40 for guiding the illumination light emitted from the integrator 20 to the mask M.

  Further, in each partial illumination optical system IL1 to IL7, a field stop (not shown) corresponding to the fields V1 to V7 on the mask M is disposed in the vicinity of the light emitting end face 20out (see FIG. 2) of the rod integrator 20. In addition, the relay optical system 40 is set so that the image of the field stop is formed on the mask M at a predetermined magnification. That is, the field stop and the mask M are optically conjugated with each other by the relay optical system 40. In the present embodiment, a portion including the rod integrator 20 and the light introducing unit 10A provided between the light source unit LS and the relay optical system 40 is used as the lighting device 1A.

  The projection optical systems PL1, PL2, PL3, PL4, PL5, PL6, and PL7 are disposed between the mask M and the plate P, and the fields of view V1 to V7 of the mask M that are respectively illuminated by the partial illumination optical systems IL1 to IL7 ( An enlarged image of the pattern in the same area as the illumination area is projected on the plate P and formed on the upper surface (exposure surface, photosensitive surface) of the plate P.

  The projection optical systems PL1, PL3, PL5, and PL7 in the first column corresponding to the first column partial illumination optical systems IL1, IL3, IL5, and IL7 aligned along the non-scanning direction (Y direction) orthogonal to the scanning direction are as follows. , Each having a field of view V1, V3, V5, V7 along the non-scanning direction on the surface (first surface) on which the pattern surface of the mask M is disposed, and the surface on which the upper surface of the plate P is disposed (second surface) Pattern images of the mask M are formed on image fields (projection areas) I1, I3, I5, and I7 arranged at predetermined intervals along the upper non-scanning direction. Similarly, the second column of projection optical systems PL2, PL4, and PL6 corresponding to the second column of partial illumination optical systems IL2, IL4, and IL6 arranged along the non-scanning direction are respectively in the non-scanning direction on the first surface. In the image fields (projection areas) I2, I4, I6 (I2 and I4 are not shown) arranged at predetermined intervals along the non-scanning direction on the second surface. Respectively.

  In FIG. 1, the partial illumination optical systems IL2 and IL4 are located on the back side of the partial illumination optical systems IL1, IL3, IL5 and IL7, and the partial projection optical systems PL2 and PL4 are the partial projection optical systems PL1 and PL1, respectively. Since it is located on the back side of PL3, PL5, and PL7, illustration is omitted.

  Further, between the projection optical system of the first row and the projection optical system of the second row, an off-axis alignment system 152 as a measurement system used for aligning the plate P, the mask M, and the plate P And an autofocus system 154 as a measurement system used for adjusting the focus position (position in the Z direction).

  The projection optical system PL1 will be described in detail as an example. As shown in FIG. 2, the projection optical system PL1 includes a concave reflecting mirror CCM arranged in the optical path between the mask M and the plate P, and the mask M. The first lens group G1 having an optical axis AX11 parallel to the Z-axis disposed in the optical path between the first lens group G1 and the concave reflecting mirror CCM, and the optical path between the first lens group G1 and the concave reflecting mirror CCM. The second lens group G2 is arranged in the optical path between the second lens group G2 and the plate P, and the light traveling from the second lens group G2 in the + Z direction is deflected in the −X direction so as to be the optical axis. A first deflecting member FM1 that extends along the optical axis AX12 crossing AX11, and the light that travels in the −X direction from the first deflecting member FM1 is disposed in the optical path between the first deflecting member FM1 and the plate P− A second deflection member FM2 for deflecting in the Z direction, and a second It is disposed in an optical path between the direction member FM2 and the plate P, and includes a third lens group G3 having an optical axis AX13 parallel to the optical axis AX11 of the first lens group G1, the.

  The optical axes of the second lens group G2 and the concave reflecting mirror CCM are the same as the optical axis AX11 of the first lens group G1. That is, the projection optical system PL1 is an off-axis optical system using the concave reflecting mirror CCM, and the light passing through the mask M that has passed through the first and second lens groups G1 and G2 is reflected again by the concave reflecting mirror CCM. After that, the field of view V1 of the mask M is projected on the plate P via the third lens group G3 via the first and second deflecting members FM1, FM2, and an image is formed in the image field I1. An aperture stop AS for determining the numerical aperture on the plate P side of the projection optical system PL1 is in the vicinity of the reflecting surface of the concave reflecting mirror CCM in the optical path between the concave reflecting mirror CCM and the second lens group G2. The aperture stop AS is positioned so that the mask M side and the plate P side are substantially telecentric. The position of the aperture stop AS can be regarded as the pupil plane of the projection optical system PL1.

  Further, the projection optical system PL1 is an effective imaging light beam by an off-axis optical system using the concave reflecting mirror CCM, with respect to the optical axes AX11 and AX13 in the first and third lens groups G1 and G3. For this reason, in each lens of the third lens group G3 composed of a larger lens, the optical axis AX13, which is a portion through which the imaging light beam does not pass, passes through the half surface on the X direction side. The half on the + X direction side is cut.

  By the way, as shown in FIG. 3, the mask M set in the exposure apparatus 100 is arranged along the non-scanning direction (Y direction), and the trapezoidal shape (arc shape, projection optical system PL1 to PL7 in FIG. 1). Alternatively, seven row pattern portions M10 to M16 in which the visual fields V1 to V7 of which the end portion may be triangular or the like may be positioned are provided. The reason why the fields of view V1 to V7 are trapezoidal is to overlap and expose images of patterns corresponding to both ends of the fields of view V1 to V7 on the plate P in order to reduce joint errors. The same pattern is alternately formed on both ends of the pattern portions M10 to M16. Here, the same pattern is alternately formed because of the imaging characteristics of the projection optical systems PL1 to PL7, with respect to the scanning direction (X direction), there are an odd number of reflecting surfaces that change the traveling direction of light to a right angle in the XZ plane. It is included and becomes an erect image because of one-time image formation, and in the non-scanning direction (Y direction), there is no reflection surface that changes the light traveling direction to a right angle in the YZ plane and is formed once. Because it becomes an inverted statue.

  However, since the images of the edge portions inside the visual fields V1 and V7 at both ends in the Y direction are portions that are not exposed to each other (because they are inverted images in the non-scanning direction), the visual fields V1 and V7 in the Y direction One end is a straight line parallel to the X axis.

  FIG. 4 shows fields V1, V3 on the mask M of the projection optical systems PL1, PL3 in the first row and image fields (projection regions) I1, I3 on the plate P, and a mask M of the projection optical system PL2 in the second row. It is a top view which shows the relationship between the upper visual field V2 and the image field I2 on the plate P. FIG. The projection optical systems PL1 to PL3 form images in the image fields I1, I2, and I3 in which the patterns in the visual fields V1, V2, and V3 are upright in the X direction and are inverted in the Y direction. The visual field V1 and the image field I1 are deviated in the −X direction from the optical axes AX11 and AX13, respectively. The visual field V2 and the image field I2 are deviated in the + X direction from the optical axes AX21 and AX23, respectively. For this reason, even if the shape of the lens constituting the third lens group G3 is rotationally asymmetrical by cutting off the half on the concave reflecting mirror CCM side, vignetting does not occur in the image forming light beam directed to the image fields I1 and I2.

Also, the X direction (scanning) of a straight line parallel to the Y axis connecting the centers VC1 etc. of the first column visual fields V1, V3 and the like and a straight line parallel to the Y axis connecting the centers VC2 etc. of the second column visual fields V2, etc. (Direction) is set to Ln, and similarly, a straight line parallel to the Y axis connecting the center IC1 etc. of the image fields I1, I3 etc. in the first row and the center IC2 etc. of the image field I2 etc. in the second row are connected If the interval in the X direction with the straight line parallel to the axis is Lp, and the projection magnification of each projection optical system PL1, PL2, PL3 is β, the relationship of equation (A) is established between the intervals Ln and Lp. .
Lp = Ln × | β | (A)

  Thereby, in the exposure apparatus 100, as shown in FIG. 3, the column pattern portions M10 and M12 for the first column projection optical system, the column pattern portions M11 and M13 for the second column projection optical system, and the like. Are formed at the same position in the X direction and the mask offset MO is set to 0, the projected images can be accurately connected on the plate P and exposed.

However, when the distance Ln and the distance Lp satisfy the relationship of the following formula (B), the two-dot chain line positions 21A to 21C in FIG. 3 correspond to the mask offset MO obtained by the following formula (C). As shown, the X-direction offset between the column pattern portions M10, M12, etc. for the first column visual fields V1, V3, etc. and the column pattern portions M11, M13, etc. for the second column visual fields V2, V4, etc. It is necessary to provide.
Lp <Ln × | β | (B)
MO = Ln−Lp / | β | (C)

  Therefore, in the exposure apparatus 100, for example, the mask M is moved at the speed VM in the + X direction indicated by the arrow SM1 (see FIG. 2) in a state in which the pattern of the mask M is projected and exposed on the plate P during the scanning exposure. In synchronization with this, the plate P moves at the speed VM × | β | in the + X direction indicated by the arrow SP1. As a result, a pattern in which images of the magnification factor β of the row pattern portions M10 to M16 of the mask M in FIG. It is also possible to scan the mask M and the plate P in the −X direction.

[Illumination device and illumination method]
Next, the lighting apparatus 1A will be described with reference to FIGS. 5 is a block diagram showing an outline of the configuration of the illumination device 1A, FIG. 6 is a perspective view showing the rod integrator 20 and the light introducing portion 10A, and FIG. 7 is a plan view showing the light incident end face 20in of the rod integrator 20. is there.

  As shown in FIG. 5, the light introducing section 10A includes condensing lenses 3A and 3B, optical fibers 4A and 4B, fiber relay lenses 5A and 5B, and an adjustment mechanism 30A. Light beams LB1 are incident on the condenser lenses 3A and 3B from the first light source unit LSa and the second light source unit LSb of the light source unit LS, respectively.

  As the light source units LSa and LSb, ones that generate a light beam LB1 having substantially the same wavelength band and the same light intensity are used. As the laser light source provided in the light source unit LS, for example, a laser light source such as an ArF excimer laser or a harmonic generation light source of a YAG laser can be used. In addition, a lamp light source such as a mercury lamp can be used instead of the laser light source. As light for exposure use, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm) light, i-line, g-line, h-line combined wave, wavelengths 193 nm, 355 nm, etc. Ultraviolet pulse light etc. can be illustrated.

  The condensing lenses 3A and 3B are set so as to condense the light beam LB1 emitted from the light source unit LS on the incident side end faces 4Ain and 4Bin of the optical fibers 4A and 4B, respectively, and guide the light beam LB1 to the optical fibers 4A and 4B. Has been. The optical fibers 4A and 4B are arranged such that the emission side end faces 4Aout and 4Bout are in a predetermined positional relationship with respect to the light incident end face 20in of the rod integrator 20 with a predetermined interval therebetween. Further, the light beams emitted from the emission side end faces 4Aout and 4Bout of the optical fibers 4A and 4B become the light beams LB2 condensed by the fiber relay lenses 5A and 5B, respectively, and the rod integrator 20 has a predetermined aperture angle (numerical aperture). It is set to enter the light incident end face 20in.

  As shown in FIG. 6, the adjustment mechanism 30A includes connection support members 6A and 6B and adjustment movable frames 7A and 7B to which these are fixed, respectively. The emission sides of the optical fibers 4A and 4B are supported by connection support members 6A and 6B, respectively. The connection support members 6A and 6B are plate-like members having a predetermined thickness, and a through hole (not shown) penetrating vertically is formed, and the emission side end face 4Aout of the optical fibers 4A and 4B is formed above the through hole. , 4Bout is supported. Lens support cylinders 8A and 8B are attached to the lower part of the through hole. In these lens support cylinders 8A, 8B, fiber relay lenses 5A, 5B are supported in a state of facing the emission side end faces 4Aout, 4Bout.

  The adjustment movable frames 7A and 7B are driven by an adjustment driving device (not shown) so as to be parallel to each other and to approach and separate from each other along the longitudinal direction (Y direction) of the light incident end face 20in of the rod integrator 20. Further, these adjustable movable frames 7A and 7B are movable in the X direction in synchronization. As described above, the adjustment mechanism 30A is symmetrical with respect to the position where the plurality (two in the present embodiment) of the light beams LB2 are incident on the light incident end face 20in of the rod integrator 20 with respect to the central axis CA of the rod integrator 20 described later. It can adjust so that it may become a position.

  The rod integrator 20 is formed of a rectangular parallelepiped glass rod formed of, for example, quartz glass, and a pair of upper and lower parallel light incident end surfaces 20in and light output end surfaces 20out, and two pairs of side surfaces 20A and 20B parallel to each other. It has side surfaces 20C and 20D (see FIG. 7), and is set to a predetermined length (length in the Z-axis direction) L. The light incident end face 20in and the light emitting end face 20out have an elongated rectangular shape. Such a rod integrator 20 reflects light incident from the light incident end face 20in by the side faces 20A, 20B, 20C, and 20D and emits light from the light emitting end face 20out.

  Hereinafter, the illumination method in 1 A of illuminating devices which concern on this embodiment is demonstrated. First, the incident position LB2s where the light beam LB2 is incident on the light incident end face 20in will be described with reference to FIG. 7 showing the light incident end face 20in of the rod integrator 20.

  In the rod integrator 20, the distance wy between the side surfaces 20A and 20B is set to be longer than the distance Wx between the side surfaces 20C and 20D which are side surface pairs located on both sides in the X direction. Further, between the side surfaces 20C and 20D where the distance Wx is sufficiently shorter than the length L, the total number of times of total reflection is increased from the light incident end surface 20in to the light emitting end surface 20out, and the X direction is The light quantity distribution is sufficiently uniformized. On the other hand, in the Y direction, since the distance Wy is set longer than the distance Wx, it is difficult to make the light amount distribution uniform compared to the X direction. The reason why the light emitting end face 20out is flat in this way is that the field of view of the projection optical systems PL1 to PL7 is flat.

  Therefore, in the present embodiment, the two light beams LB2 are set to enter along the Y direction (longitudinal direction) on the light emitting end face 20in. Here, the position where the light beam LB2 is incident on the light incident end face 20in is defined as an incident position LB2s. As shown in FIG. 7, the two incident positions LB2s are arranged on the line Sy in the Y direction (longitudinal direction) passing through the central axis CA of the rod integrator 20 on the light incident end face 20in, with the central axis CA being the center of symmetry. It is arranged to be. In other words, the two incident positions LB2s are set symmetrically with respect to the center position (center axis CA) between the side surface 20A and the side surface 20B along the direction (Y direction) in which the side surfaces 20A and 20B face each other. Has been.

  In this embodiment, as shown in FIGS. 5 and 6, the optical axis LB2c of the fiber relay lenses 5A and 5B is set to be perpendicular to the light incident end face 20in. 7, the distance between the two incident positions LB2s is the length of the line segment Sy, that is, the distance wy (the length in the longitudinal direction of the light incident end face 20in), and the number of light beams LB2 (this embodiment). Then, the length wy / 2 divided by 2) is set. In other words, the interval between the two incident positions LB2s adjacent to each other is set to a length wy / 2 obtained by dividing the distance wy between the side faces 20A, 20B by the number of the incident positions LB2s along the direction in which the side faces 20A, 20B face each other. Has been. Thus, by setting the arrangement of the incident position LB2s with respect to the light incident end face 20in, the uniformity of the illuminance distribution (light quantity distribution) of the emitted light from the light emitting end face 20out of the rod integrator 20 is improved.

  In general, a part of the light beam LB2 incident on the light incident end face 20in of the rod integrator 20 goes straight and exits as it is from the light exit end face 20out, but has an incident angle greater than a predetermined size based on the configuration of the rod integrator 20. The light beam LB2 reaches the side surfaces 20A and 20B. The light beam LB2 is totally reflected by the side surfaces 20A and 20B, and after the total reflection by the side surfaces 20A and 20B is repeated until the light emitting end surface 20out is reached, it is emitted from the light emitting end surface 20out. As a result, the light beam LB2 incident on the rod integrator 20 is folded and integrated by the width of the rod integrator 20, and is emitted from the light emitting end face 20out. By this integration, the light intensity is averaged at the light emitting end face 20out, and a uniform intensity distribution is obtained.

  Next, the effect | action by the rod integrator 20 is demonstrated using FIG. Originally, there is also a spread in the depth direction (X direction in this embodiment), but for convenience of explanation, we will look at the situation in a two-dimensional plane.

  A light beam LB2 having a Gaussian distribution with an incident angle θ is incident on a position shifted by a dimension d from the center (central axis CA) of the light incident end face 20in of the rod integrator 20 having a length L and a width wy. FIG. 8 shows a state where the incident angle θ is large and is reflected once by the side surface 20A and reaches the light emitting end surface 20out. If reflection on the side surface 20A of the rod integrator 20 is not considered, the situation is the same as when light is incident on a parallel plate having a thickness (length) L as indicated by a broken line. The incident light beam LB2 has a Gaussian distribution, as indicated by a broken line V in FIG. 8, but is actually reflected by the side surface 20A and folded at the light emitting end surface 20out as shown by the solid line S. Is accumulated. The integrated result is the light quantity distribution at the light emitting end face 20out. The amount of light at an arbitrary point y in the Y direction on the light exit end face 20out can be approximately expressed by the following equation 1. In Expression 1, the width in the Y direction of the rod integrator 20 is w, the refractive index of the glass (quartz glass) constituting the rod integrator 20 is n, and the aperture angle (light incident end face) of the light beam LB2 incident on the rod integrator 20 The numerical aperture at 20 inches is indicated by NA.

  Here, as an index indicating the performance of the rod integrator 20, L × NA / (n × w) in the case of the maximum number of times the light beam LB2 incident on the rod integrator 20 is reflected in the rod integrator 20 is considered. If the light beam LB2 is reflected a sufficient number of times in the rod integrator 20 having a long length L and a narrow width w, the flatness of the illuminance distribution on the exit surface is improved. In reality, it is desirable that the length L of the rod integrator 20 is made as small as possible due to restrictions on the apparatus size and the workability of optical parts, and the numerical aperture NA of the light beam LB2 is as small as possible because of the ease of arrangement of the optical system. The index L × NA / (n × w) indicating the performance of the integrator 20 is desirably a small value.

  In FIG. 9, a single beam LB2 having a Gaussian distribution with a numerical aperture NA of 0.20 is applied to a rod integrator 20 made of quartz having a length (L) of 400 mm and a width (wy) of 36 mm at the center of the light incident end face 20in. The result of having calculated the light quantity distribution in the light-projection end surface 20out when it injects perpendicularly to is shown. The index L × NA / (n × w) indicating the performance of the rod integrator 20 at this time is about 1.5. In FIG. 9, the horizontal axis represents the coordinate in the width direction at the light emitting end surface 20out with the origin as the center of the light emitting end surface 20out, and the vertical axis represents the emission normalized by the value at the center of the light emitting end surface 20out. Taking light. As described above, when the light beam LB2 is incident perpendicularly to the center of the light incident end face 20in, the light emitting end face 20out has a light intensity decrease of 0.011% from the center (periphery), but considerably high illuminance uniformity. Indicates.

  In FIG. 10, the horizontal axis represents an index L × NA / (n × w) indicating the performance of the rod integrator 20 from 1 to 2, and the vertical axis represents the light emitting end face 20out as an index indicating the illuminance uniformity of the rod integrator 20. It is a figure which shows the result of having plotted the value which normalized the illumination intensity in the extreme end (end part of the width direction) with the value of the center of the light emission end surface 20out. As shown in FIG. 10, it can be seen that the illuminance uniformity is exponentially improved with respect to the index L × NA / (n × w) indicating the performance of the rod integrator 20.

  FIG. 11 shows a case where a single beam LB2 having a Gaussian distribution of NA = 0.20 under the same conditions as above is applied to the rod integrator 20 (rod integrator made of quartz having a length of 400 mm and a width of 36 mm) as follows. Illuminance distribution at the light exit end face 20out when the light incident end face 20in is shifted to three positions in the width direction (longitudinal direction) from the center of the light entrance end face 20in (the amount of emitted light normalized by the center value of the light exit end face 20out). Distribution). In FIG. 11, a case where the light beam LB2 is incident with a shift of 3 mm in the width direction from the center of the light incident end face 20in is indicated by a broken line, a case where the light beam LB2 is incident with a shift of 6 mm is indicated by a one-dot chain line, and a case where the light beam LB2 is incident with a shift of 9 mm. Shown with a chain line. As shown in the figure, since the light beam LB2 is deviated from the center of the light incident end face 20in, the illuminance uniformity has an inclination component. Since the amount of light at the center of the light exit end face 20out hardly changes, the deviation in illuminance uniformity at the extreme end position (position 18 mm from the center) of the light exit end face 20out is about 3% and 6 mm when shifted by 3 mm. The relationship is approximately 6% when shifted and approximately 8.5% when shifted by 9 mm, which is approximately proportional to the length of the shift.

  Next, since the illumination light has an inclined component depending on the incident position of the light beam LB2, the two light beams LB2 are arranged along the longitudinal direction of the light emitting end surface 20in so as to be symmetric with respect to the center of the light incident end surface 20in. Let's consider making it incident on the position of the location and eliminating the tilt component. FIG. 12 shows that two incident light beams LB2 with NA = 0.20 have distances from the center of the light exit end face 20in of ± 3 mm (dashed line), ± 6 mm (one-dot chain line), and ± 9 mm (two-dot chain line), respectively. Illustrated is the illuminance distribution (distribution of the emitted light quantity normalized by the value at the center of the light emitting end face 20out) at the light emitting end face 20out in such a case. The solid line plots the amount of emitted light when one light beam LB2 with NA = 0.20 is placed in the center of the rod integrator 20.

As shown in FIG. 12, it can be seen that the illuminance uniformity is completely flat when the two light beams LB2 are incident at a distance of 9 mm (two-dot chain line) from the center. This is a state in which the distance (18 mm) between the two light beams LB2 is exactly ½ of the width W (36 mm) of the rod integrator 20. At this time, as shown in FIG. 13, the light beam LB2 vertically incident with a deviation of d1 and d2 from the central axis CA of the rod integrator 20 is drawn as a solid line below the light exit end face 20out on the exit surface of FIG. It has a Gaussian distribution. The light intensity at that time can be expressed by Equation 2 below.

At this time, the intensity difference Δ between the center x = 0 and the periphery x = w / 2 of the light emitting end face 20out can be expressed by the following Expression 3.

  When the index L × NA / (n × w) indicating the performance of the rod integrator 20 is relatively small, the ratio of the amount of light reaching the light emitting end surface 20out without being reflected by the side surfaces 20A and 20B as shown in FIG. Many. Therefore, in the above equation, calculation is made so that there is no difference in the amount of light when k = 0, and d1 = w / 4 and d2 = −w / 4. As shown in FIG. 13, this is equivalent to a state where the incident light beams LB2 (incidence positions LB2s) are arranged at equal intervals when viewed from the light emitting end face 20out.

  Further, even when the number of light beams LB2 is increased, the illumination intensity uniformity can be maintained by arranging the incident light beams LB2 (incident positions LB2s) to be arranged at equal intervals when viewed from the light emitting end face 20out. . When the number of incident light beams is n, the distance between the incident positions LB2s with respect to the width w of the rod integrator 20 is w / n, and a line is formed with respect to the center of the light incident end face 20in along the longitudinal direction of the rod integrator 20. Uniform illumination can be obtained by arranging them symmetrically.

  FIG. 14 shows a state on the light incident end face 20in when three light beams LB2 are introduced into the light incident end face 20in. When three light beams LB2 are incident on the light incident end surface 20in, one light beam LB2 is incident on the center of the light incident end surface 20in, and the light beams LB2 are spaced apart from each other at intervals W / 3 on both sides in the longitudinal direction of the light beam LB2. , The uniformity of the illuminance distribution on the light exit end face 20out side can be achieved.

  FIG. 15 shows a state on the light incident end face 20in when four light beams LB2 are entered. When four light beams LB2 are inserted, the light beams LB2 are incident on positions along the longitudinal direction that are symmetric with respect to the center of the light emitting end face 20in, and the interval between the incident positions LB2s of the light beams LB2 is set to W / 4. Thereby, the uniformity of the illuminance distribution on the light emitting end face 20out side can be achieved. In addition, it is preferable to set the light intensity of each light beam LB2 to be the same.

  In FIG. 16, when the two light beams LB2 are incident on the light incident end surface 20in, the light emission end surface 20out has a uniform light emission amount (solid line), and the interval between the light beams LB2 is narrowed (broken line). The case where the space | interval of a light beam is expanded is shown (a dashed-dotted line). The emitted light quantity shown on the vertical axis in FIG. 16 indicates a value normalized by the center value of the light emitting end face 20out. From this, it can be seen that the illuminance uniformity can be controlled by adjusting the interval between the incident positions of the two light beams LB2 along the longitudinal direction so that the center of the light incident end face 20in becomes the center of symmetry. Note that even when the number of light beams LB2 is three as shown in FIG. 14 or when the number of light beams LB2 is four as shown in FIG. 15, the illuminance uniformity on the light emitting end face 20out side can be controlled.

  However, even if uniform illumination is obtained at the light emitting end face 20out, for example, when the illumination apparatus 1A is applied to the exposure apparatus 100, an aberration or an antireflection coating when passing through an illumination relay lens, a condenser lens, a projection lens, or the like. The peripheral light amount may be reduced due to the angle characteristics of the lens, and the peripheral light amount may be reduced on the plate P (photosensitive substrate). In order to compensate for such a decrease in the amount of light, it is possible to cope with such an illuminance distribution as shown by a one-dot chain line in FIG.

  However, when the index L × NA / (n × w) indicating the performance of the rod integrator 20 is high to some extent, the averaging effect is too strong to be corrected. Since the illuminance uniformity required in the above exposure apparatus or the like is about 1%, the index L × NA / (n × W) indicating the performance of the rod integrator 20 is relatively small to control this illuminance uniformity. It must be in the range of not less than 0.0 and not more than 2.0, and more preferably in the range of about 1 to 1.5.

  As described above, the adjustment of the position of the light beam LB2 incident on the rod integrator 20 uses the adjustment mechanism 30A shown in FIGS. As shown in FIG. 6, the position adjustment 30A of the light beam LB2 can be realized by moving the adjustment movable frames 7A and 7B in the Y-axis direction (distance direction of the side surfaces 20A and 20B). In this adjustment mechanism 30A, the adjustment movable frames 7A and 7B are arranged such that the light beams LB are line-symmetric with respect to the center axis CA of the rod integrator along the line segment Sy passing through the center of the light incident end face 20in. It is preferable that it is set so as to move in synchronization with. Such an adjustment mechanism 30A has an effect of facilitating the control for flattening the illuminance distribution on the light emitting end face 20out as shown in FIG. In addition, in 1 A of illuminating devices which concern on this embodiment, although the light introduction part 10A is a structure provided with the adjustment mechanism 30A, as an illuminating device, you may not provide the adjustment mechanism 30A.

  In the illuminating device 1A according to the present embodiment, the illuminance of the illumination light emitted from the light emitting end face 20out is uniform, and a high illumination light quantity is obtained by the propagation of light without waste in the rod integrator 20. Therefore, the exposure performance such as the uniformity of the illuminance distribution of the exposure light of the exposure apparatus 100 to which the illumination apparatus 1A is applied can be improved.

  In the exposure apparatus 100, the adjustment mechanism 30A in the illumination apparatus 1A may be adjusted as follows. That is, as shown in FIGS. 6 and 7, the adjustment mechanism 30 </ b> A has the adjustment movable frames 7 </ b> A and 7 </ b> B such that the light beams LB are aligned with respect to the central axis CA of the rod integrator along the line segment Sy on the light incident end surface 20 in. To be always line symmetric. Moreover, uniform illuminance can be obtained by arranging the incident positions LB2s so that the interval between the incident positions LB2s is wy / 2 with respect to the width wy of the rod integrator 20.

  By adjusting the positional relationship between the incident positions LB2s on the light incident end face 20in while maintaining a line symmetric relation with respect to the center line CA of the rod integrator 20, the illuminance uniformity at the light emitting end face 20out is expressed as a quadratic function. Ingredients can be adjusted. For this reason, in the exposure apparatus 100 according to the present embodiment, it is possible to compensate for a decrease in the amount of light around the field of view due to the lens coating of the projection optical apparatus PL, and to ensure illuminance uniformity.

  As a specific operation method for making the illuminance distribution of the exposure light uniform, for example, if the exposure light has a tilt component in the exposure area on the surface of the plate P, the incident light beam is shifted toward the lower light amount, and projection optics is used. If the center of each exposure region where the exposure light emitted from the systems PL1 to PL7 is incident is high, the light beams entering the substantially symmetrical position with respect to the center of the rod integrator 20 are separated by the same amount. What is necessary is just to adjust so that it may be moved and illuminance may become uniform.

  In the present embodiment, for example, the illuminance distribution of the exposure light may be calculated by one illuminance sensor (not shown), and a plurality of calibrations are performed on the stage (not shown) that holds the plate P. It is good also as a structure which arrange | positions an illumination intensity sensor and detects illumination intensity distribution at once.

  The work for correcting the illuminance uniformity of the exposure light depends on the stability of the light source and the apparatus, but if it is stable, the work is performed when the exposure apparatus 100 is assembled or when apparatus maintenance such as lamp replacement is performed. It's okay. In the case where the illuminance uniformity is not stable, a light transmission area is formed in addition to the pattern projection area on the mask (reticle) M, and an illuminance sensor (not shown) on the stage (not shown) immediately before the exposure operation. It is desirable to start the exposure operation by measuring the amount of illumination light and adjusting the position of the light beam LB2 incident on the rod integrator 20 as described above so that the illumination state is always uniform.

  Such an adjustment mechanism 30A has an effect of facilitating the control for flattening the illuminance distribution of the light emitting end face 20out on the light emitting end face 20out as shown by the solid line in FIG. It goes without saying that even if the illuminance is uneven as it passes through the projection optical apparatus PL or the like, the illuminance distribution can be made uniform by performing such adjustment.

[Second Embodiment]
FIGS. 17-19 are related with the illuminating device 1B which concerns on the 2nd Embodiment of this invention. As shown in FIG. 18, the illumination device 1 </ b> B includes a light introducing unit 10 </ b> B and a rod integrator 20. In the present embodiment, the light incident end face 20in and the light exit end face 20out (not shown) have a rectangular illumination region having a length (depth) in the X direction. That is, as shown in FIGS. 17 and 18, a plurality (two) of light beams LB2 are also incident on the light incident end face 20in in the depth direction (X direction), so that a total of four light beams LB2 are incident. It has become. As shown in FIGS. 18 and 19, the illumination device 1B according to the second embodiment includes an adjustment mechanism 30B having a configuration different from that of the first embodiment.

  As shown in FIGS. 17 to 19, in this embodiment, the four light beams LB2 incident on the light incident end face 20in are two line segments Sx extending in the X direction and 2 extending in the Y direction on the light incident end face 20in. It is set to be incident on the four incident positions LB2s where the line segments Sy intersect.

  Below, the determination method of line segment Sx, Sy is demonstrated using FIG. The width dimension in the X direction of the light incident end face 20in is wx, and the width dimension in the Y direction is wy. In FIG. 17, the pair of line segments Sx extending along the X direction on the light incident end face 20in is located at a distance of wy / 4 from the sides on the side faces 20A and 20B. Therefore, the interval between the pair of line segments Sx is wy / 2. The pair of line segments Sy extending along the Y direction on the light incident end face 20in is located at a distance of wx / 4 from the sides on the side faces 20C and 20D. Therefore, the interval between the pair of line segments Sy is wx / 2. The point where these four line segments Sx and Sy intersect is the incident position LB2s, and the center line of the four light beams LB2 is set to overlap the incident position LB2s. Therefore, the two incident positions LB2s arranged along the four line segments Sx and Sy are set to be symmetric with respect to the centers Sxc and Syc of these line segments Sx and Sy.

  Such position adjustment of the incident position LB2s is performed by the adjusting mechanism 30B shown in FIGS. In this case, it is desirable that the position adjustment of the incident light beam LB2 can be performed independently in each of the X direction and the Y direction.

  Hereinafter, the adjustment mechanism 30 </ b> B will be described with reference to FIGS. 18 and 19. The adjusting mechanism 30B is disposed so as to face the light incident end face 20in. The adjustment mechanism 30B includes a pair of X-direction adjustment movable frames 31A and 31B that extend along the Y direction and are arranged in parallel with each other, and a pair of Y-direction adjustment that extends along the X direction and are arranged in parallel with each other. Movable frames 32A and 32B.

  The X direction adjustment movable frames 31A and 31B can move only in the X direction, and the Y direction adjustment movable frames 32A and 32B can move only in the Y direction. That is, the pair of X-direction adjusting movable frames 31A and 31B and the pair of Y-direction adjusting movable frames 32A and 32B are always close to and separated from each other while maintaining a parallel state. As shown in FIGS. 18 and 19, the pair of X-direction adjusting movable frames 31A and 31B are arranged slightly below the pair of Y-direction adjusting movable frames 32A and 32B. As shown in FIG. They are arranged so as to intersect when seen in a plane.

  As shown in FIG. 18, guide slits 33 are formed on the side surfaces of the X-direction adjusting movable frames 31A and 31B and the Y-direction adjusting movable frames 32A and 32B along the respective longitudinal directions. The movable body 34 is for X direction adjustment at each of four positions where the X direction adjustment movable frames 31A and 31B and the Y direction adjustment movable frames 32A and 32B intersect in plan view. The movable frames 31A, 31B and the guide slits 33 of the Y-direction adjusting movable frames 32A, 32B are provided so as to be slidable.

  The moving body 34 includes a lower slide portion 35 slidable on the lower X-direction adjustment movable frames 31A and 31B, and an upper slide portion slidable on the Y-direction adjustment movable frames 32A and 32B. 36. Therefore, the lower slide portions 35 of the four moving bodies 34 are slidably provided in the guide slits 33 of the X direction adjustment movable frames 31A and 31B, and the upper slide portion 36 is guided by the Y direction adjustment movable frames 3LS and 3LS. The slit 33 is slidably provided.

  The lower slide portion 35 and the upper slide portion 36 include a slide block (not shown) that can slide in the corresponding X-direction adjustment movable frames 31A and 31B and the Y-direction adjustment movable frames 32A and 32B, and a guide slit 33, respectively. Are connected through.

  As shown in FIG. 18, the lower slide part 35 and the upper slide part 36 are integrally coupled by a connecting cylinder 37. A lens support tube 38 is provided below the lower slide portion 35 so as to protrude downward in the vertical direction. A fiber relay lens (not shown) is mounted in the lens support tube 38 so that the tube center axis and the optical axis coincide. The upper slide portion 36 is provided so that the connecting cylinder 37 penetrates and protrudes upward. Then, optical fibers 4A, 4B, 4C, and 4D are mounted on a connecting cylinder 37 that protrudes above the upper slide portion 36 so that each end portion faces a fiber relay lens (not shown).

  In the adjustment mechanism 30B having such a configuration, the movable body 34 can be moved in the X direction by moving the pair of X-direction adjustment movable frames 31A and 31B close to and away from each other along the X direction. At this time, the pair of moving bodies 34 arranged along the X direction always form one row in the X direction. The moving body 34 can be moved in the Y direction by moving the pair of movable frames 32A and 32B for Y direction adjustment close to and away from each other along the Y direction. At this time, the pair of moving bodies 34 arranged along the Y direction always form one row in the Y direction.

  By using such an adjustment mechanism 30B, four incident positions LB2s at which a light beam LB2 emitted from a fiber relay lens (not shown) is incident on the light incident end face 20in are four rectangular shapes having vertical and horizontal sides in the XY directions. It is possible to move while maintaining the state of forming a vertex. Note that in order to translate the pair of X-direction adjusting movable frames 31A and 31B and the pair of Y-direction adjusting movable frames 32A and 32B so as to approach and separate from each other, the mutually parallel frames are mutually threaded. May be connected by a ball screw having a reverse thread portion.

  By using the adjustment mechanism 30B, as shown in FIG. 17, a pair of incident positions LB2s forming a row in the Y direction are arranged so that the interval between them is wy / 2, and a pair of incident positions LB2s forming a row in the X direction. The two incident positions LB2s arranged along the four line segments Sx and Sy are arranged so as to be symmetrical with respect to the centers Sxc and Syc. It becomes easy.

  Further, by using the adjusting mechanism 30B, it is possible to easily perform fine adjustment while considering the positional balance of the four incident positions LB2s while maintaining the positional relation of the four incident positions LB2s as described above. . In order to maintain the positional balance in this way, the center of the distance between the X-direction adjusting movable frames 31A and 31B may always be on the center line of the width dimension in the X direction of the light incident end face 20in. Similarly, the center of the distance between the Y-direction adjusting movable frames 32A and 32B may always be on the center line of the width dimension in the Y direction of the light incident end face 20in. When the adjustment is completed by the adjustment mechanism 30B, the X-direction adjustment movable frames 31A and 31B and the Y-direction adjustment movable frames 3LS and 3LS may be fixed.

  The present embodiment is a case where the four incident positions LB2s are arranged in 2 rows × 2 rows on the light incident end face 20in, but an arbitrary number of m rows × n rows depending on the shape and size of the light incident end face 20in. Beam LB2 can be made incident. As described above, in the lighting device 1B according to the present embodiment, it is possible to improve the illuminance uniformity at the light emitting end face 20out even for the rod integrator 20 having the rectangular light incident end face 20in having a relatively large area. it can. Therefore, the exposure performance of the exposure apparatus to which the illumination device 1B is applied can be improved.

[Third Embodiment]
Next, an illuminating device 1C according to a third embodiment of the present invention will be described with reference to FIG. The configuration of the illumination device 1 </ b> C according to the present embodiment includes a light introducing unit 10 </ b> C and a rod integrator 20. The illuminating device 1C includes fiber relay lenses 5C and 5D arranged in parallel with each other so that the optical axes are common instead of the fiber relay lenses 5A and 5B used in the illuminating device 1A according to the first embodiment. The light introduction part 10C used is provided. Other configurations in the present embodiment are the same as those in the first embodiment described above.

  In this embodiment, since the fiber relay lenses 5C and 5D are arranged, the fiber relay lenses 5C and 5D are made common by the optical fibers 4A and 4B, and reduced and projected, whereby the emission-side end faces 4Aout and 4Aout of the optical fibers 4A and 4B are obtained. It is also possible to adjust by loosening the position tolerance of 4Bout. In this embodiment, as shown in FIG. 20, in order to adjust the interval of the light beam LB2 emitted from the fiber relay lens 5D, the emission side end faces 4Aout and 4Bout of the optical fibers 4A and 4B are set in the direction indicated by the arrow y. All you need to do is translate. In the present embodiment, the output-side end faces 4Aout and 4Bout of the optical fibers 4A and 4B are connected using the adjustment mechanism 30C having the same configuration as the adjustment mechanism 30A of the illumination device 1A according to the first embodiment described above. What is necessary is just to support to support member 6A, 6B (refer FIG. 6).

  In the illuminating device 1C according to the present embodiment, similarly to the illuminating device 1A according to the first embodiment described above, the illuminance of the illumination light irradiated from the light emitting end surface 20out is uniform, and the waste in the rod integrator 20 is lost. A high amount of illumination light can be obtained by the propagation of light without light. Therefore, if this illumination apparatus 1C is applied to the exposure apparatus 100 instead of the illumination apparatus 1A, uniform exposure light can be obtained, so that the exposure performance can be improved.

[Fourth Embodiment]
FIG. 21 shows a schematic configuration of a lighting device 1D according to the fourth embodiment of the present invention. In addition, the incident position on the light incident end face 20in in this embodiment is the same as that in the first embodiment shown in FIG. As illustrated in FIG. 21, the lighting device 1D is schematically configured to include a light introducing unit 10D and a rod integrator 20. The illumination device 1D can be used in place of the illumination device 1A of the projection exposure apparatus according to the first embodiment. The illumination device 1D according to the present embodiment can improve the uniformity of illuminance distribution and particularly the telecentricity of illumination light.
(Configuration of light introduction part)

  As shown in FIG. 21, in the present embodiment, the light introducing section 10D includes condensing lenses 3A and 3B, optical fibers 4A and 4B, fiber relay lenses 5A and 5B, and an adjustment mechanism 30D. Has been.

  As shown in FIG. 21, the condensing lenses 3A and 3B condense the light beams LB1 emitted from the first light source part LSa and the second light source part LSb on the incident side end faces 4Ain and 4Bin of the optical fibers 4A and 4B, respectively. The light beams are set to guide the light beams into the optical fibers 4A and 4B. The optical fibers 4 </ b> A and 4 </ b> B are arranged so that the emission-side end faces 4 </ b> Aout and 4 </ b> Bout are arranged at a predetermined interval along the Y direction and are in a line-symmetric relationship with respect to the central axis CA of the rod integrator 20.

  Further, as shown in FIG. 21, the light emitted from the emission side end faces 4Aout and 4Bout of the optical fibers 4A and 4B becomes a light beam LB2 condensed by the fiber relay lenses 5A and 5B, respectively, and is emitted at a predetermined opening angle. It is set so as to be incident on the incident end face 20in. Further, the angle formed by the center line LB2c of the light beam LB2 and the light incident end face 20in is such that the center line of the light beam LB2 passing through the rod integrator 20 (shown by a broken line in the figure) passes through the center 20outc of the light emitting end face 20out. Set to.

  As shown in FIG. 21, the adjusting mechanism 30D integrally holds the optical fibers 4A and 4B and the fiber relay lenses 5A and 5B, and the light beam LB2 emitted from the fiber relay lenses 5A and 5B to the light incident end surface 20in. The incident angle and the interval between the incident positions LB2s can be adjusted.

  The arrangement of the incident position LB2s incident on the light incident end face 20in in the illumination device 1D according to the present embodiment is the same as that in the first embodiment shown in FIG.

  In the present embodiment, as illustrated in FIG. 7, the light beam LB2 is incident on two (a plurality of) incident positions LB2s arranged along the Y direction having the width dimension wy on the light incident end face 20in. It has become. The two incident positions LB2s pass through the central axis CA of the rod integrator 20 at the light incident end face 20in, and are on the line Sy over the width wy of the light incident end face 20in in the Y direction (longitudinal direction). Arrange them so that they are symmetrical.

  In particular, in the present embodiment, as shown in FIG. 21, the two light beams LB2 are incident on the light incident end surface 20in at a predetermined angle so that the center line LB2c passes through the center 20outc of the light emitting end surface 20out. Is set to That is, the light beam LB2 incident from the light incident end face 20in is set to go to the center 20outc of the light emitting end face 20out. Further, as shown in FIG. 7, the distance between the incident positions LB2s is the length of the line segment Sy passing through the center of the light incident end face 20in, that is, the width wy divided by the number of light beams LB2 (2 in this embodiment). It is set to wy / 2.

  In this embodiment, as shown in FIG. 7, the incident position LB2s is set to the above-described arrangement with respect to the light incident end face 20in, and the two light beams LB2 introduced into the rod integrator 20 are centered 20outc of the light emitting end face 20out. The telecentricity of the illumination light that is the outgoing light from the light outgoing end face 20out can be improved. Furthermore, in this illuminating device 1D, the light quantity distribution (intensity distribution) of the illumination light which is the emitted light from the light emission end face 20out can be made uniform.

  The light beam LB2 incident on the rod integrator 20 is incident on the position of the light beam LB2 on the light incident end face 20in and the light beam LB2 by the adjusting mechanism 30D supported by the fiber relay lenses 5A and 5B and the optical fibers 4A and 4B. Adjustment with the incident angle which injects into the end surface 20in is enabled.

  Some of the light rays incident on the rod integrator 20 go straight to the light exit end face 20out, but the other light rays are reflected by the side surface of the rod integrator 20 as shown in FIG. The reflection is repeated toward the light emitting end face 20out. Therefore, as shown in FIG. 8, the light beam LB2 incident on the rod integrator 20 is folded and overlapped with the width wy of the rod integrator 20, and the light intensity on the light emitting end face 20out becomes almost uniform. When viewed from one point on the light emitting end face 20out, it can be understood that light from the images of the respective light beams LB2 on the light incident end face 20in at the folded point is added. At this time, the sum of only the amount of light gives the illuminance distribution. Further, when the weighted average of the incident azimuths of the respective light beams is taken with the light intensity, the traveling direction of the light beam center (center line) can be calculated.

  Output from the light output end face 20out when light having a Gaussian distribution with an aperture light flux of 0.3 is incident on the center of the light incident end face 20in having a length of 200 mm, a width of 32 mm, and a refractive index with respect to air of 1.5. The light quantity distribution is plotted in FIG. 22, and the emission angle direction is plotted in FIG. In addition, the emitted light quantity shown on the vertical axis | shaft of FIG. 22 has shown the value normalized by the emitted light quantity of the center of the light emission end surface 20out.

  As shown in FIG. 22, since the number of times of folding in the rod integrator 20 is slightly small, a light amount decrease of about 0.3% is seen with respect to the center. As shown in FIG. 23, with respect to the emission angle azimuth, the light emission end face 20out and the both ends in the width direction (Y direction) emit substantially perpendicularly, whereas the light emission end face 20out has both ends in the width direction. It can be seen that at a position on the center side by wy / 4, the light beam is emitted with an inclination of 0.79 mrad in the direction of spreading from the center.

  Here, a case where a plurality of light beams LB2 are incident on the rod integrator 20 is considered. First, as shown in FIG. 7, the incident positions LB2s of the two light beams LB2 are set apart from each other by half the width wy of the light incident end face 20in, and symmetrically arranged with respect to the center of the light incident end face 20in. Two LB2 are made to enter perpendicularly to the light incident end face 20in. FIG. 24 shows the illuminance distribution by each light beam LB2 by a broken line and a one-dot chain line, and shows the combined illuminance distribution by a solid line. As shown in FIG. 24, when the two light beams LB2 are incident in the above-described positional relationship, the illuminance distribution is almost canceled and the uniformity is fairly good. In addition, the emitted light quantity shown on the vertical axis | shaft of FIG. 24 has shown the value normalized by the emitted light quantity of the center of the light emission end surface 20out.

  FIG. 25 shows the result of calculating the emission angle azimuth. In FIG. 25, similarly to FIG. 24, the illuminance distribution by the individual light beams LB2 is indicated by a broken line and an alternate long and short dash line, and the illuminance distribution when both the light beams LB2 are combined is indicated by a solid line. When the position of incidence on the rod integrator 20 is shifted, the emission angle azimuth at the center of the light emission end face 20out changes, but the peripheral part where the side faces are close does not change.

  Further, in FIG. 25, when the emission angle azimuth of the light beam when the two incident light beams LB2 are combined, it is about 0.58 mrad at the position of wy / 4 from both ends in the width direction of the light emission end face 20out. This is a slight improvement over the case where exactly one incident light beam LB2 is placed in the center of the rod integrator 20 (see FIG. 23).

  FIG. 26 plots the state of the outgoing angle azimuth when the incident angle of the two incident light beams LB2 is left as it is and the incident angle is directed inward (inward so that the light beams LB2 approach each other). In FIG. 26, the solid line indicates that the incident light beam LB2 is put in parallel with the central axis CA of the rod integrator 20, and the alternate long and short dash line indicates that the center line LB2c of the incident light beam LB2 passes through the center of the light exit end face 20out. A broken line shows the case where it entered with the intermediate incident angle. From this, it can be seen that the variation in the emission angle azimuth is small in the state of the one-dot chain line.

  Therefore, the relationship between the emission angle azimuth and the inclination of the incident light beam LB2 at the point where the variation of the emission angle azimuth is the largest, that is, the point separated from the center of the light emission end face 20out by ¼ of the width wy of the rod integrator 20 is shown. This is shown in FIG. In FIG. 27, the vertical axis represents the outgoing angle azimuth (rad.), And the horizontal axis represents the inclination of the incident light beam. From FIG. 27, it can be seen that when the center line LB2c of the incident light beam LB2 passes through the center of the light emitting end face 20out, the deflection of the outgoing angle azimuth is minimized.

  FIG. 28 shows a path of light emitted from a point separated from the center of the light emitting end face 20out by ¼ of the width wy of the rod integrator 20. As shown in FIG. 28, since the interval of the light beam LB2 incident on the rod integrator 20 is 1/2 of the width wy of the rod integrator 20 and is arranged at a position symmetrical to the central axis of the rod integrator 20, the light emitting end face 20out The incident light beams LB2 viewed from the side are arranged at equal intervals. For this reason, the emission azimuths of the emitted light beams are arranged at a substantially constant angle. Further, since the emission point y shown in FIG. 28 is on the right side, the outgoing light beam is also arranged on the outside side. Unless the position incident on the rod integrator 20 is changed, the optical path along which the light beam travels does not change. Inclining the light beam LB2 incident on the rod integrator 20 changes the amount of light passing through each light beam. The traveling direction of the light beam reflected an odd number of times on the side surface of the rod integrator 20 is reversed.

  Therefore, when the incident light beam LB2 is tilted with respect to the light incident end face 20in, the light amount change of the even-numbered reflected light beam and the light amount change of the odd-numbered reflected light beam are reversed. For each light beam, the emission direction of the rod integrator 20, the incident direction, the light amount when the incident light beam LB2 is vertical (light intensity), and the light amount when the center line LB2c of the incident light beam LB2 passes through the center of the light output end face 20out ( The light intensity is shown in Table 1 below.

  In Table 1, L is the length of the rod integrator 20, w is the width in the longitudinal direction of the rod integrator 20, n is the refractive index of the rod integrator 20, and NA is the numerical aperture of the incident light beam LB2. When the center line LB2c of the incident light beam LB2 is incident so as to pass through the center 20outc of the light exit end face 20out, the ratio of the intensity of each light beam to the two incident light beams LB2 is equal. The averaging by the rod integrator 20 is due to the light reflected from the side surfaces being folded back and overlapping. Therefore, in order to minimize the shift in telecentricity, the gradient components of the light intensity with respect to the emission position must be equal.

として解くと、

より、（ｎ・ｗ）／（ＮＡ・Ｌ）＞０．４０２を得る。同様に、

として解くと、

より、（ｎ・ｗ）／（ＮＡ・Ｌ）＜０．７１７を得る。つまり、テレセントリシティのずれを最小にするには、０．４０２＜（ｎ・ｗ）／（ＮＡ・Ｌ）＜０．７１７を満たす必要がある。 In this embodiment, the incident light has a Gaussian distribution I (x) = Exp {−2x ^ 2}, but the Gaussian distribution ranges from I (0.1) ≈0.98 to I (0.897) ≈0. It seems that the slope is almost uniform in the range of .2. Therefore, in order to allow the light beam forming the illumination light to enter this range, the maximum value of the light intensity value at the center of the emission end in Table 1 is when the following equation 4 is satisfied:

As

(N · w) / (NA · L)> 0.402 is obtained. Similarly,

As

(N · w) / (NA · L) <0.717 is obtained. In other words, in order to minimize the telecentricity deviation, it is necessary to satisfy 0.402 <(n · w) / (NA · L) <0.717.

  FIG. 29 shows the illuminance (emitted light amount) uniformity when the angle azimuth of the emitted light beam at the point y (see FIG. 28) on the light emitting end face 20out is close to perpendicular to the light emitting end face 20out. The emitted light quantity shown on the vertical axis in FIG. 29 shows a value normalized by the emitted light quantity at the center of the light emitting end face 20out. In FIG. 29, the solid line indicates that the incident light beam LB2 is placed parallel to the center axis CA of the rod integrator 20, and the alternate long and short dash line indicates that the center line LB2c of the incident light beam LB2 passes through the center of the light exit end face 20out. A broken line shows the case where it entered with the intermediate incident angle. In this example, it can be seen that the peripheral portion is lowered by about 0.3% compared to the central portion of the light emitting end face 20out. There is a trade-off relationship between the degree of illuminance uniformity and the variation in the angular orientation of the emitted light beam.

  When the illumination apparatus 1D of the present embodiment is applied to a scanning projection exposure apparatus, it is possible to control the illuminance uniformity within the scanning range, so it is important to suppress the variation in the angle of the illumination light beam. In this case, it is desirable to arrange the light introducing portion 10D so that the center line LB2c of the incident light beam LB2 passes through the center 20outc of the light emitting end face 20out. Further, even if the number of light beams incident on the rod integrator 20 is increased to three or four, if the center line IL2c of each incident light beam LB2 passes through the center 20outc of the light output end surface 20out, the light output end surface The fluctuation of the angle direction of the light beam emitted from 20out can be minimized.

  Furthermore, in the illuminating device 1D according to the present embodiment, the illuminance uniformity and the angle characteristic of the emitted light beam may be balanced to obtain an intermediate angle as necessary. In addition, the effect of the rod integrator has been described in a plane for the sake of simplification, but it is possible to cope with an illumination area close to a square by similarly providing an angle in the depth direction. Further, when a flat illumination area is provided as in a scanning exposure apparatus, a rod integrator 20 adapted to the flat illumination area is used. At this time, since integration by the rod integrator 20 is sufficiently performed in the short direction, the present invention may be applied only in the longitudinal direction by arranging incident light beams only in the longitudinal direction.

  In the present embodiment, it is possible to minimize the deviation of telecentricity that occurs when the rod integrator 20 as the illumination uniformizing element is used. Therefore, when used in the exposure apparatus 100 according to the first embodiment, even if there is a focus change, the transfer position and the magnification change hardly occur, the pattern transfer performance is good, and the yield of the electronic device is improved. An illumination optical system that contributes to this can be provided.

[Electronic device manufacturing method]
Next, a predetermined pattern (circuit pattern, electrode pattern, etc.) is formed on the glass substrate (plate P) using the scanning (projection) exposure apparatus 100 according to the first embodiment shown in FIG. By doing so, the liquid crystal display element as an electronic device can also be obtained. Hereinafter, a method for manufacturing a liquid crystal display device as an example of a method for manufacturing an electronic device will be described with reference to the flowchart of FIG.

  In step S11 (pattern formation process) of FIG. 30, first, a liquid crystal display element using the exposure apparatus 100 described above, an application process in which a photoresist is applied onto a glass substrate to be exposed to prepare a plate P as a photosensitive substrate. An exposure process for transferring and exposing the pattern of the mask M on the photosensitive substrate and a developing process for developing the photosensitive substrate are performed. A predetermined resist pattern is formed on the plate P by a lithography process including the coating process, the exposure process, and the development process. Subsequent to this lithography process, a predetermined pattern including a large number of electrodes and the like is formed on the plate P through an etching process using the resist pattern as a mask, a resist stripping process, and the like. The lithography process or the like is executed a plurality of times according to the number of layers on the plate P.

  In the next step S12 (color filter formation step), a large number of groups of three fine filters corresponding to red R, green G, and blue B are arranged in a matrix on one substrate constituting the liquid crystal cell, Alternatively, a substrate having a color filter is manufactured by arranging a set of three stripe-shaped filters of red R, green G, and blue B in the horizontal scanning line direction. In the next step S13 (cell assembly process), for example, a liquid crystal sealing region (space) is divided into a substrate having a plate P having a predetermined pattern obtained in step S11 and a color filter obtained in step S12. The liquid crystal panel (liquid crystal cell) is manufactured by laminating through a sealing material and injecting liquid crystal into the liquid crystal sealing region.

  In subsequent step S14 (module assembly process), the liquid crystal panel (liquid crystal cell) assembled in this manner is attached with an electric circuit for performing a display operation, and components such as a backlight, and a liquid crystal as an electronic device. Completed as a display element.

  According to the above-described method for manufacturing a liquid crystal display element, when the exposure apparatus 100 exposes the plate P coated with the photoresist, the illuminance uniformity of the illumination light emitted from the illumination apparatus 1A is high. The illuminance uniformity of the exposure light that has passed through the optical system (light guide optical system), the mask M, and the projection optical device PL is also high, and the photoresist can be uniformly exposed. Therefore, since the pattern of the mask M can be accurately transferred to the plate P, a liquid crystal panel with high pattern accuracy can be manufactured. For this reason, according to this embodiment, the manufacturing yield of electronic devices including a liquid crystal display element can be improved.

[Other Embodiments]
Each embodiment has been described above. However, it should not be understood that the description and the drawings, which constitute a part of the disclosure of these embodiments, limit the present invention. The scope of the present invention is not limited to the illustrated and described exemplary embodiments, but includes all embodiments that provide the same effects as those intended by the present invention. Further, the scope of the invention is not limited to the combinations of features of the invention defined by the claims, but may be defined by any desired combination of particular features among all the disclosed features.

  For example, in each of the above embodiments, the light introduction units 10A to 10D are provided with the adjustment mechanisms 30A to D. However, in addition to the adjustment mechanisms 30A to 30D, position adjustment means including various movement adjustment means is used. Can do. Further, the illumination device may have a configuration without the adjustment mechanism as long as the incident position and the incident angle of the light beam LB2 incident on the light incident end face 20in are set to the above-described conditions.

  Further, in each of the above embodiments, an example in which the light emitted from the light source unit LS is guided to the optical fibers 4A and 4B by the condensing lenses 3A and 3B has been shown. 20 may be used.

  Further, in the fourth embodiment, the light beam LB2 is incident on the light incident end surface 20in with the center of the light incident end surface 20in as the center of symmetry, and the center line of the light beam LB2 passing through the rod integrator 20 is the light emitting end surface 20out. The distance between the incident positions of the light beam LB2 is set to be a length obtained by dividing the width wy of the integrator 20 by the number of the light beams LB2, but the distance between the incident positions of the light beam LB2 is It does not have to be a length obtained by dividing wy by the number of light beams LB2. In that case, the incident angle of the light beam LB2 with respect to the light incident end surface 20in may be set so that the illumination light emitted from the light emitting end surface 20out is emitted along a direction perpendicular to the light emitting end surface 20out.

  Note that the illumination devices 1A to 1D according to the above-described embodiment can be used as illumination devices such as a projector in addition to the exposure device.

DESCRIPTION OF SYMBOLS 1A-D Illumination device 3A, 3B Condensing lens 4A, 4B Optical fiber 5A-D Fiber lens 6A, 6B Connection support member 7A, 7B Adjustable movable frame 8A, 8B Lens support cylinder 10A-D Light introduction part 20 Rod integrator 20A -D side surface 20in light incident end surface 20out light emitting end surface 30A-D adjustment mechanism 31A, 31B movable frame for X direction adjustment 32A, 32B movable frame for Y direction adjustment 33 guide slit 34 moving body 35 lower slide portion 36 upper slide portion 37 Connecting cylinder 38 Lens holding cylinder 40 Relay optical system 100 Exposure apparatus IL1-7 Partial illumination optical system IU Illumination section LS Light source section LB1, LB2 Light beam LB2s Incident position M Mask P Plate PL Projection optical apparatus PL1-7 Projection optical system

Claims (15)

A light incident end face, a light exit end face, and first and second side faces opposite to each other; the light incident from the light entrance end face is reflected by the first and second side faces; An illumination device that includes a rod integrator that emits light, and irradiates illumination light with illumination light via the rod integrator,
A light introduction part for allowing the illumination light to enter the rod integrator from a plurality of incident positions on the light incident end face;
The plurality of incident light beams are set in a symmetrical arrangement with respect to a center position between the first side surface and the second side surface along a direction in which the first and second side surfaces oppose each other. An illumination apparatus, wherein the illumination light is incident on the rod integrator from a position.   The interval between the incident positions adjacent to each other among the plurality of incident positions is set to a length obtained by dividing the distance between the first and second side surfaces along the facing direction by the number of the plurality of incident positions. The lighting device according to claim 1, wherein:   3. The illumination according to claim 1, wherein the light introducing unit causes the illumination light to be incident on the rod integrator from each of the plurality of incident positions toward the center of the light emitting end surface. apparatus.   4. The illumination device according to claim 1, wherein the light introduction unit includes an adjustment mechanism that adjusts at least one of a position and an angle of the illumination light incident on the light incident end surface. 5. . The distance from the light incident end surface of the rod integrator to the light emitting end surface is L, the distance between the first and second side surfaces is w, the refractive index of the rod integrator is n, and the illumination light is incident on the rod integrator. When the numerical aperture of is indicated by NA,
0.402 <(n · w) / (NA · L) <0.717
The lighting device according to any one of claims 1 to 4, wherein: A light incident end face, a light exit end face, and first and second side faces opposite to each other; the light incident from the light entrance end face is reflected by the first and second side faces; An illumination method for irradiating an illumination target with illumination light via a rod integrator that emits light,
A plurality of incident positions on the light incident end face that are set symmetrically with respect to a center position between the first side face and the second side face along a direction in which the first and second side faces oppose each other. The illumination method includes causing the illumination light to enter the rod integrator.   The interval between the incident positions adjacent to each other among the plurality of incident positions is set to a length obtained by dividing the distance between the first and second side surfaces along the opposing direction by the number of the plurality of incident positions. The illumination method according to claim 6, further comprising:   The illumination method according to claim 6, further comprising causing the illumination light to enter the rod integrator from each of the plurality of incident positions toward the center of the light emitting end surface.   The lighting device according to claim 6, further comprising adjusting at least one of a position and an angle of the illumination light incident on the light incident end surface. The distance from the light incident end surface of the rod integrator to the light emitting end surface is L, the distance between the first and second side surfaces is w, the refractive index of the rod integrator is n, and the illumination light is incident on the rod integrator. When the numerical aperture of is indicated by NA,
0.402 <(n · w) / (NA · L) <0.717
The lighting device according to claim 6, further comprising satisfying An exposure apparatus that exposes a photosensitive substrate with light through a pattern formed on a mask,
An exposure apparatus comprising the illumination device according to claim 1 that illuminates the mask.   The exposure apparatus according to claim 11, further comprising a projection optical system that projects the pattern onto the photosensitive substrate with light passing through the pattern.   The exposure apparatus according to claim 12, wherein the projection optical system projects an enlarged image of the pattern onto the photosensitive substrate.   The exposure apparatus according to any one of claims 11 to 13, wherein the photosensitive substrate has a side length or a diagonal length larger than 500 mm. Using the exposure apparatus according to any one of claims 11 to 14 to transfer the pattern to the photosensitive substrate;
And a step of processing the photosensitive substrate to which the pattern is transferred.

Images