JP4749682B2 - Exposure equipment - Google Patents

Description

  The present invention relates to an exposure apparatus, and more particularly to an exposure apparatus that performs high-precision digital exposure with near-field light.

In recent years, various near-field optical heads that perform high-density recording and fine processing using near-field light (evanescent light) have been proposed. For example, an exposure head has been proposed in which a minute opening is formed at the tip of a sharpened optical fiber, laser light is introduced from the other end, and the photosensitive material is exposed using evanescent light that oozes out from the minute opening ( Patent Document 1). In this exposure head, optical fiber cores are two-dimensionally arranged, and laser light is introduced into an optical fiber core at a position corresponding to a bit pattern of information to be written. As an optical head that is easy to manufacture, a near-field optical head in which a light-shielding film having a minute aperture is provided on the light exit side of a lens array has been proposed (Patent Document 2).
JP 2002-123965 A, paragraphs 0038-0039, FIG. JP 2000-228554 A

  However, Patent Document 1 does not describe specific means for introducing laser light into an optical fiber core at a position corresponding to a bit pattern of information. The diameter of the optical fiber core is about several μm, and there is a problem that it is difficult to introduce laser light with high coupling efficiency into each of the two-dimensionally arranged optical fiber cores.

  Also, Patent Document 2 does not describe specific means for introducing laser light into the lens array. In this case as well, it is difficult to introduce the laser light with the optical axis aligned for each lens of the lens array.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide an exposure apparatus capable of performing high-precision digital exposure with high light utilization efficiency using near-field light. There is to do.

In order to achieve the above object, a first exposure apparatus of the present invention includes a light source that emits a light beam for illumination and a plurality of pixel units each having a light modulation state that changes in accordance with a control signal. A spatial light modulator that modulates a light beam incident on the plurality of pixel units from the light source for each pixel unit, and a plurality of microlenses arranged two-dimensionally at a pitch corresponding to the plurality of pixel units. A microlens array for condensing the light beam modulated by the pixel unit for each microlens, and a core and a clad formed in a taper shape at a pitch corresponding to a condensing position of the plurality of microlenses. and a head portion for each of the incident end is two-dimensionally arranged in a plurality of optical fibers sharpened diameter of several tens to several hundreds of about 100nm is the emission end Te, the exit end of said plurality of optical fibers From each Wherein the exposing the photosensitive material in the near-field light out is.

  In the first exposure apparatus of the present invention, the light beam incident on the spatial light modulation element from the light source is modulated for each pixel part of the spatial light modulation element, and the light beam modulated by the pixel part is micro-array of the microlens array. Condensed for each lens.

  In the head portion, incident ends of the plurality of optical fibers are two-dimensionally arranged at a pitch corresponding to the condensing positions of the plurality of microlenses. Therefore, the light beam modulated for each pixel portion of the spatial light modulator and condensed by the microlens array is efficiently incident on each of the incident ends of the plurality of optical fibers arranged in the head portion. The emission ends of the plurality of optical fibers are sharpened, and the photosensitive material is exposed with near-field light leaking from the sharpened emission ends. That is, using near-field light, high-precision digital exposure can be performed with high light utilization efficiency.

  In the first exposure apparatus, the incident ends of the plurality of optical fibers can be fixedly arranged, and the emission ends of the plurality of optical fibers can be moved. For example, by increasing the length of the optical fiber, the incident end of the optical fiber can be fixedly arranged and the exit end can be moved.

In the second exposure apparatus according to the reference example, a light source that emits a light beam for illumination and a plurality of pixel units each having a light modulation state that changes according to a control signal are two-dimensionally arranged. A spatial light modulation element that modulates the light beam incident on the plurality of pixel units for each pixel unit, and a plurality of microlenses arranged two-dimensionally at a pitch corresponding to the plurality of pixel units, A microlens array for condensing the light beam modulated by the unit for each microlens, and a plurality of microlens arrays at a pitch corresponding to a condensing position of the plurality of microlenses. A light-shielding film in which each of the micro openings is two-dimensionally arranged, and the photosensitive material is exposed with near-field light leaking from each of the plurality of micro openings.

In the second exposure apparatus according to the reference example, the light beam incident on the spatial light modulation element from the light source is modulated for each pixel part of the spatial light modulation element, and the light beam modulated by the pixel part is transmitted from the microlens array. Light is collected for each microlens. The light exit surface of the microlens array is provided with a light-shielding film in which a plurality of minute openings are two-dimensionally arranged at a pitch corresponding to the condensing position of the plurality of microlenses. Therefore, the light beam modulated for each pixel portion of the spatial light modulator is efficiently incident on each microlens.

  The light exit surface of the microlens array is provided with a light-shielding film in which a plurality of minute openings are two-dimensionally arranged at a pitch corresponding to the condensing position of the plurality of microlenses. The photosensitive material is exposed with the near-field light leaking from the plurality of minute openings. That is, using near-field light, high-precision digital exposure can be performed with high light utilization efficiency.

Further, the third exposure apparatus according to the reference example includes a light source that emits a light beam for illumination and a plurality of pixel units whose light modulation states change according to control signals, which are two-dimensionally arranged, and the light source A spatial light modulation element that modulates the light beam incident on the plurality of pixel units for each pixel unit, and a plurality of first microlenses are arranged two-dimensionally at a pitch corresponding to the plurality of pixel units. A first microlens array for condensing the light beam modulated by the pixel unit for each of the first microlenses, and a plurality of light beams at a pitch corresponding to a condensing position of the plurality of first microlenses. A light guide unit in which incident ends of the optical fiber are two-dimensionally arranged, and a plurality of second microlenses are two-dimensionally arranged at a pitch corresponding to the outgoing end of the optical fiber, and are emitted from the optical fiber. Said light beam A second microlens array for condensing each of the two microlenses, and a plurality of microlenses at a pitch corresponding to the condensing position of the plurality of second microlenses, provided on the light exit surface of the second microlens array. And a light-shielding film in which each of the minute openings is two-dimensionally arranged, and the photosensitive material is exposed with near-field light leaking from each of the plurality of minute openings.

In the third exposure apparatus according to the reference example, the light beam incident on the spatial light modulation element from the light source is modulated for each pixel part of the spatial light modulation element, and the light beam modulated by the pixel part is The light is collected for each first microlens of the lens array. In the light guide section, each of the incident ends of the plurality of optical fibers is two-dimensionally arranged at a pitch corresponding to the condensing position of the plurality of first microlenses. The light beam modulated by the first microlens array and efficiently incident on each of the incident ends of the plurality of optical fibers arranged in the light guide is guided.

  In the second microlens array, a plurality of second microlenses are two-dimensionally arranged at a pitch corresponding to the emission end of the optical fiber, and the light beam guided by the light guide unit is the second one. The light is condensed for each second microlens of the microlens array. Accordingly, the light beam is efficiently incident on each of the second microlenses. The light exit surface of the second microlens array is provided with a light-shielding film in which each of a plurality of minute openings is two-dimensionally arranged at a pitch corresponding to the condensing position of the plurality of second microlenses. . The photosensitive material is exposed with near-field light leaking from each of the plurality of minute openings. That is, using near-field light, high-precision digital exposure can be performed with high light utilization efficiency.

  In order to achieve the above object, a fourth exposure apparatus of the present invention includes a light source that emits a light beam for illumination and a plurality of pixel units each having a light modulation state that changes in accordance with a control signal. A spatial light modulator that modulates a light beam incident on the plurality of pixel units from the light source for each pixel unit, and a plurality of first microlenses at a pitch corresponding to the plurality of pixel units. Corresponding to the first microlens array for condensing the light beam modulated by the pixel unit for each of the first microlenses and the condensing positions of the plurality of first microlenses. A light guide unit in which each of the incident ends of the plurality of optical fibers is arranged two-dimensionally at a pitch, and a plurality of second microlenses are arranged two-dimensionally at a pitch corresponding to the emission end of the optical fiber, Emitted from the optical fiber A second microlens array that collects the light beam for each of the second microlenses, and a plurality of third microlenses at a pitch corresponding to the condensing position of the plurality of second microlenses. A third microlens array that condenses each of the light beams incident in the second microlens array, which is dimensionally arranged, for each of the third microlenses, and the light emission of the third microlens array. Each of the plurality of micro openings is provided with a light-shielding film provided on a surface and in which each of the plurality of micro openings is two-dimensionally arranged at a pitch corresponding to a condensing position of the plurality of third micro lenses. The photosensitive material is exposed with near-field light leaking from the surface.

In the fourth exposure apparatus of the present invention, the light beam incident on the spatial light modulation element from the light source is modulated for each pixel portion of the spatial light modulation element, and the light beam modulated by the pixel portion is the first microlens. Light is collected for each first microlens of the array. In the light guide section, each of the incident ends of the plurality of optical fibers is two-dimensionally arranged at a pitch corresponding to the condensing position of the plurality of first microlenses. The light beam modulated by the first microlens array and efficiently incident on each of the incident ends of the plurality of optical fibers arranged in the light guide is guided.

  In the second microlens array, a plurality of second microlenses are two-dimensionally arranged at a pitch corresponding to the emission end of the optical fiber, and the light beam guided by the light guide unit is the second one. The light is condensed for each second microlens of the microlens array. Accordingly, the light beam is efficiently incident on each of the second microlenses.

  In the third microlens array, a plurality of third microlenses are two-dimensionally arranged at a pitch corresponding to the condensing position of the plurality of second microlenses. The light beam condensed on the third microlens array is collected for each third microlens of the third microlens array. Therefore, the light beam is efficiently incident on each of the third microlenses.

  The light exit surface of the third microlens array is provided with a light-shielding film in which each of the plurality of minute openings is two-dimensionally arranged at a pitch corresponding to the condensing position of the plurality of third microlenses. . The photosensitive material is exposed with near-field light leaking from each of the plurality of minute openings. That is, using near-field light, high-precision digital exposure can be performed with high light utilization efficiency.

  According to the exposure apparatus of the present invention, there is an effect that digital exposure can be performed with high light utilization efficiency and high accuracy using near-field light.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[First Embodiment]
(Schematic configuration of exposure apparatus)
As shown in FIG. 1, the exposure apparatus according to the first embodiment uses a digital micromirror device (DMD) as a spatial light modulation element that modulates an incident light beam for each pixel in accordance with image data. 110 is provided. The DMD 110 is connected to a controller (not shown) that includes a data processing unit and a mirror drive control unit. The data processing unit of this controller generates a control signal for driving and controlling each micromirror of the DMD 110 based on the input image data. Further, the mirror drive control unit controls the angle of the reflection surface of each micromirror of the DMD 110 based on the control signal generated by the image data processing unit. The control of the angle of the reflecting surface will be described later.

  On the light incident side of the DMD 110, a fiber array light source 112 having a laser emitting portion in which emission ends (light emitting points) of optical fibers are arranged in a line along a predetermined direction, and laser light emitted from the fiber array light source 112 A lens system 114 that corrects the light and condenses the light on the DMD, and mirrors 122 and 124 that reflect the laser light transmitted through the lens system 114 toward the DMD 110 are arranged in this order.

  The lens system 114 includes a pair of combination lenses 116 that collimate the laser light emitted from the fiber array light source 112, a rod integrator 118 that corrects the light quantity distribution of the collimated laser light, and It is composed of a condensing lens 120 that condenses the laser light with the corrected light quantity distribution on the DMD. Since the rod integrator 118 guides the light while totally reflecting the light inside the integrator, the rod integrator 118 can correct the laser light so that the light quantity distribution is uniform.

  Further, on the light reflection side of the DMD 110, magnifying lens systems 126 and 128 for magnifying the DMD image reflected by the DMD 110 are arranged. At a position where a DMD image is formed by the magnifying lens systems 126 and 128, a microlens array 130 in which a microlens is provided corresponding to each pixel of the DMD is disposed. A near-field array head 132 is disposed on the light exit side of the microlens array 130. The near-field array head 132 is disposed close to the surface of the photosensitive material 134 so as to expose the photosensitive material 134 with near-field light.

  As shown in FIG. 2, the near-field array head 132 is configured by bundling a plurality of optical fibers 136 including a core 140 and a clad 142. At the incident end of the optical fiber 136, the cores 140 are arranged in a matrix corresponding to the light collection positions of the microlens array 130. An end 138 on the emission side of the optical fiber 136 is sharpened to a diameter of about several tens to several hundreds of nm, and a minute opening is formed at the tip. When laser light is introduced from the other end of the optical fiber 136, evanescent light oozes out from this minute opening.

  FIG. 2 shows an example in which 28 optical fibers 136 are bundled and the cores 140 are arranged in a matrix of 4 rows and 7 columns, but in reality, the microfibers arranged in the microlens array 130 are shown. The near-field array head 132 is configured by bundling the same number of optical fibers 136 as the lenses.

  As shown in FIG. 3, the DMD 110 includes a micromirror 62 supported by a support column on an SRAM cell 60, and a large number of (pixels) (pixels). For example, the mirror device is configured by arranging 600 × 800 micromirrors in a lattice pattern. Each pixel is provided with a micromirror 62 supported by a support column at the top, and a material having a high reflectance such as aluminum is deposited on the surface of the micromirror 62. The reflectance of the micromirror 62 is 90% or more. A silicon gate CMOS SRAM cell 60 manufactured in a normal semiconductor memory manufacturing line is disposed directly below the micromirror 62 via a support including a hinge and a yoke, and is entirely monolithic (integrated type). ).

  When a digital signal is written in the SRAM cell 60 of the DMD 110, the micromirror 62 supported by the support is tilted in a range of ± α degrees (for example, ± 10 degrees) with respect to the substrate side on which the DMD 110 is disposed with the diagonal line as the center. It is done. 4A shows a state in which the micromirror 62 is tilted to + α degrees in the on state, and FIG. 4B shows a state in which the micromirror 62 is tilted to −α degrees in the off state. Therefore, by controlling the tilt of the micromirror 62 in each pixel of the DMD 110 according to the image signal as shown in FIG. 3, the light incident on the DMD 110 is reflected in the tilt direction of each micromirror 62. .

  FIG. 3 shows an example of a state in which a part of the DMD 110 is enlarged and the micromirror 62 is controlled to + α degrees or −α degrees. On / off control of each micromirror 62 is performed by a controller (not shown) connected to the DMD 110. A light absorber (not shown) is arranged in the direction in which the light beam is reflected by the micromirror 62 in the off state.

  As shown in FIG. 5A, the fiber array light source 112 includes a plurality of (25 in the figure) laser modules 64, and one end of the multimode optical fiber 30 is coupled to each laser module 64. Yes. An optical fiber 31 having the same core diameter as that of the multimode optical fiber 30 and a cladding diameter smaller than that of the multimode optical fiber 30 is coupled to the other end of the multimode optical fiber 30, as shown in FIG. A laser emitting portion 68 is configured by arranging a plurality of rows (three rows in the drawing) of emitting ends (light emitting points) of the optical fiber 31 along a predetermined direction.

  The multimode optical fiber 30 and the optical fiber 31 may be any of a step index type optical fiber, a graded index type optical fiber, and a composite type optical fiber. For example, a step index type optical fiber manufactured by Mitsubishi Cable Industries, Ltd. can be used. In the present embodiment, the multimode optical fiber 30 and the optical fiber 31 are step index type optical fibers, and the multimode optical fiber 30 has a cladding diameter = 125 μm, a core diameter = 50 μm, NA = 0.2, an incident end face. The transmittance of the coat is 99.5% or more, and the optical fiber 31 has a cladding diameter = 60 μm, a core diameter = 50 μm, and NA = 0.2.

  However, the cladding diameter of the optical fiber 31 is not limited to 60 μm. The clad diameter of the optical fiber used in the conventional fiber light source is 125 μm, but the depth of focus becomes deeper as the clad diameter becomes smaller. Therefore, the clad diameter of the multimode optical fiber is preferably 80 μm or less, more preferably 60 μm or less. Preferably, it is 40 μm or less. On the other hand, since the core diameter needs to be at least 3 to 4 μm, the cladding diameter of the optical fiber 31 is preferably 10 μm or more.

  The laser module 64 is configured by a combined laser light source (fiber light source) shown in FIG. This combined laser light source includes a plurality of (for example, seven) chip-like lateral multimode or single mode GaN-based semiconductor lasers LD1, LD2, LD3, LD4, LD5, LD6, arrayed and fixed on the heat block 10. And LD7, collimator lenses 11, 12, 13, 14, 15, 16, and 17 provided corresponding to each of the GaN-based semiconductor lasers LD1 to LD7, one condenser lens 20, and one multi-lens. Mode optical fiber 30. The number of semiconductor lasers is not limited to seven. For example, as many as 20 semiconductor laser beams can be incident on a multimode optical fiber having a cladding diameter = 60 μm, a core diameter = 50 μm, and NA = 0.2. In addition, the number of optical fibers can be further reduced.

  The GaN-based semiconductor lasers LD1 to LD7 all have the same oscillation wavelength (for example, 405 nm), and the maximum output is also all the same (for example, 100 mW for the multimode laser and 30 mW for the single mode laser). As the GaN-based semiconductor lasers LD1 to LD7, lasers having an oscillation wavelength other than the above 405 nm in a wavelength range of 350 nm to 450 nm may be used. A suitable wavelength range will be described later.

  As shown in FIGS. 11 and 12, the combined laser light source is housed in a box-shaped package 40 having an upper opening together with other optical elements. The package 40 includes a package lid 41 created so as to close the opening thereof. After the deaeration process, a sealing gas is introduced, and the package 40 and the package lid 41 are closed by closing the opening of the package 40 with the package lid 41. 41. The combined laser light source is hermetically sealed in a closed space (sealed space) formed by 41.

  A base plate 42 is fixed to the bottom surface of the package 40, and the heat block 10, a condensing lens holder 45 that holds the condensing lens 20, and the multimode optical fiber 30 are disposed on the top surface of the base plate 42. A fiber holder 46 that holds the incident end is attached. The exit end of the multimode optical fiber 30 is drawn out of the package from an opening formed in the wall surface of the package 40.

  Further, a collimator lens holder 44 is attached to the side surface of the heat block 10, and the collimator lenses 11 to 17 are held. An opening is formed in the lateral wall surface of the package 40, and wiring 47 for supplying a driving current to the GaN-based semiconductor lasers LD1 to LD7 is drawn out of the package through the opening.

  In FIG. 12, in order to avoid complication of the figure, only the GaN semiconductor laser LD7 is numbered among the plurality of GaN semiconductor lasers, and only the collimator lens 17 is numbered among the plurality of collimator lenses. is doing.

  FIG. 13 shows the front shape of the mounting portion of the collimator lenses 11-17. Each of the collimator lenses 11 to 17 is formed in a shape obtained by cutting a region including the optical axis of a circular lens having an aspherical surface into a long and narrow plane. This elongated collimator lens can be formed, for example, by molding resin or optical glass. The collimator lenses 11 to 17 are closely arranged in the arrangement direction of the light emitting points so that the length direction is orthogonal to the arrangement direction of the light emitting points of the GaN-based semiconductor lasers LD1 to LD7 (left and right direction in FIG. 13).

  On the other hand, each of the GaN-based semiconductor lasers LD1 to LD7 includes an active layer having a light emission width of 2 μm, and each of the laser beams B1 in a state parallel to the active layer and a divergence angle in a direction perpendicular to the active layer, for example, 10 ° and 30 °. A laser emitting ~ B7 is used. These GaN-based semiconductor lasers LD1 to LD7 are arranged so that the light emitting points are arranged in a line in a direction parallel to the active layer.

Accordingly, in the laser beams B1 to B7 emitted from the respective light emitting points, the direction in which the divergence angle is large coincides with the length direction and the divergence angle is small with respect to the elongated collimator lenses 11 to 17 as described above. Incident light is incident in a state where the direction coincides with the width direction (direction perpendicular to the length direction). That is, the collimator lenses 11 to 17 have a width of 1.1 mm and a length of 4.6 mm, and the horizontal and vertical beam diameters of the laser beams B1 to B7 incident thereon are 0.9 mm and 2. 6 mm. Each of the collimator lenses 11 to 17 has a focal length f ₁ = 3 mm, NA = 0.6, and a lens arrangement pitch = 1.25 mm.

The condensing lens 20 is formed by cutting a region including the optical axis of a circular lens having an aspheric surface into a long and narrow shape in parallel planes, and is long in the arrangement direction of the collimator lenses 11 to 17, that is, in a horizontal direction and short in a direction perpendicular thereto. Is formed. The condenser lens 20 has a focal length f ₂ = 23 mm and NA = 0.2. This condensing lens 20 is also formed by molding resin or optical glass, for example.

  In the fiber array light source 66 configured in this way, the laser beams B1, B2, B3, B4, B5, B6, and the like emitted from each of the GaN-based semiconductor lasers LD1 to LD7 constituting the combined laser light source, and Each of B7 is collimated by the corresponding collimator lenses 11-17. The collimated laser beams B <b> 1 to B <b> 7 are collected by the condenser lens 20 and converge on the incident end face of the core 30 a of the multimode optical fiber 30.

  The collimating lenses 11 to 17 and the condensing lens 20 constitute a condensing optical system, and the condensing optical system and the multimode optical fiber 30 constitute a multiplexing optical system. That is, the laser beams B1 to B7 condensed as described above by the condenser lens 20 enter the core 30a of the multimode optical fiber 30 and propagate through the optical fiber to be combined with one laser beam B. The light is emitted from the optical fiber 31 coupled to the output end of the multimode optical fiber 30.

  In each laser module, when the coupling efficiency of the laser beams B1 to B7 to the multimode optical fiber 30 is 0.85 and each output of the GaN-based semiconductor lasers LD1 to LD7 is 30 mW (when a single mode laser is used). Can obtain a combined laser beam B with an output of 180 mW (= 30 mW × 0.85 × 7) for each of the optical fibers 31 arranged in an array. Therefore, the output from the laser emitting unit 68 in which 25 optical fibers 31 are arranged in an array is about 4.5 W (= 180 mW × 25).

  In the laser emitting portion 68 of the fiber array light source 66, high-luminance light emitting points are arranged along the main scanning direction as described above. A conventional fiber light source that couples laser light from a single semiconductor laser to a single optical fiber has a low output, so a desired output could not be obtained unless multiple rows are arranged. Since the combined laser light source used in the form has a high output, a desired output can be obtained even with a small number of columns, for example, one column. In the exposure apparatus of the present embodiment, since the diameter of the light emitting region of the fiber array light source 112 is small, the angle of the light beam that passes through the lens system 114 and enters the DMD 110 becomes small, and as a result, enters the near-field array head 132. The angle of the light beam becomes smaller. That is, the near-field array head 132 can be focused with a sufficiently small spot diameter and the depth of focus can be increased, so that high-efficiency optical coupling can be achieved with the near-field array head 132.

For example, in a conventional fiber light source in which a semiconductor laser and an optical fiber are coupled on a one-to-one basis, a laser having an output of about 30 mW (milliwatt) is usually used as the semiconductor laser, and the core diameter is 50 μm and the cladding diameter is 125 μm. If a multimode optical fiber with a numerical aperture (NA) of 0.2 can be used and an output of about 4.5 W (watts) is to be obtained, 225 (15 × 15) multimode optical fibers must be bundled. Since the area of the light emitting region is 3.6 mm ² (1.9 mm × 1.9 mm), the luminance at the laser emitting portion 68 is 1.25 (W / mm ² ), and the luminance per optical fiber is 10 (W / mm ² ).

On the other hand, in the present embodiment, as described above, an output of about 4.5 W can be obtained with 25 multimode optical fibers, and the area of the light emitting region at the laser emitting portion 68 is 0.2 mm ² (0 .18 mm × 1.13 mm), the luminance at the laser emitting portion 68 is 22.5 (W / mm ² ), and the luminance can be increased by 18 times compared to the conventional case. Further, the luminance per optical fiber is 90 (W / mm ² ), and the luminance can be increased by about 9 times compared with the conventional one.

  As a semiconductor laser constituting the combined laser light source, a blue laser having an oscillation wavelength near 400 nm is suitable. When the blue laser is used, the condensed beam of the microlens array 130 can be reduced. As a result, it is possible to optically couple to the array head with high efficiency, and to supply high intensity light to the array head. In addition, even if the near-field array head has 10 million pixels, the focused light of the microlens array can be narrowed down and high intensity light can be introduced into the array head. It can be a sufficiently practical value.

  In addition, although the example which combines the light from a single mode laser was shown above, the light source output with higher brightness can be obtained by combining and combining light from a multi-mode high-power laser (for example, 200 mW). It is also possible to obtain. For example, when each output of the multimode laser is 200 mW, a combined laser beam B having an output of 1 W (= 200 mW × 0.85 × 6) can be obtained for each of the optical fibers 31 arranged in an array. it can. Therefore, the output from the laser emitting unit 68 in which the five optical fibers 31 are arranged in an array is about 5 W (= 1 W × 5).

  In addition, the case where a plurality of semiconductor lasers are combined has been described so far, but the case where a semiconductor laser and an optical fiber are coupled one-to-one without being combined and combined with a fiber at the tip. Similarly, an optical fiber having a small clad diameter (for example, a clad diameter of 60 μm and an equivalent core diameter) may be coupled. Particularly in this case, it is preferable to use a multimode high-power laser (200 mW) as the semiconductor laser, and a high-intensity light source can be obtained by using such a high-power laser. In this case, the luminance can be reduced by a factor of 4 with respect to the structure in which the semiconductor laser and the optical fiber are coupled on a one-to-one basis.

(Exposure device operation)
Next, the operation of the exposure apparatus will be described. In this exposure apparatus, when image data is input to a controller (not shown), the controller generates a control signal for driving and controlling each micromirror of the DMD 110 based on the input image data, and the DMD 110 based on the generated control signal. The angle of the reflection surface of each micromirror is controlled.

  The illumination light emitted from the light source 112 to the DMD 110 via the lens system 114 is reflected and modulated in a predetermined direction according to the angle of the reflection surface of each micromirror, and the modulated light is transmitted by the magnifying lens systems 126 and 128. Enlarged. The light magnified by the magnifying lens systems 126 and 128 is incident on each of the microlenses provided in the microlens array 130.

  The light collected by the microlens array 130 enters the corresponding cores 140 arranged in a matrix on the near-field array head 132 and guides the light in the optical fiber 136. Since the light condensed by the microlens array 130 is incident on the core 140 corresponding to the microlens, it can be efficiently incident. Further, as described above, the condensing spot of the light beam incident on the near-field array head 132 can be reduced and the depth of focus is increased, so that kicking is reduced and the coupling efficiency is increased. Then, evanescent light oozes out from the minute opening formed at the exit side end 138 of the optical fiber 136, and the photosensitive material 134 is exposed with this evanescent light.

  The beam diameter of the light beam collected by the microlens array 130 is preferably the same as the diameter of the core 140 of the optical fiber 136. By setting the same size, the coupling efficiency of the light beam to the optical fiber 136 is increased. For example, when a single mode fiber having a core diameter of 4 μm is used, in order to achieve high coupling efficiency, the condensed beam and the optical fiber have the same beam diameter, and the collected light is used for mode matching. The beam diameter of the beam is also 4 μm.

  As described above, in the exposure apparatus of the present embodiment, the microlens of the microlens array is arranged corresponding to each pixel portion of the DMD, and the microlens arranged in the microlens array is arranged close to the microlens array. Since the optical fiber cores of the field array head are arranged, the light modulated by the DMD and collected by the microlens can be efficiently incident on the corresponding optical fiber core. That is, using near-field light, high-precision digital exposure can be performed with high light utilization efficiency.

  In particular, in this embodiment, since a high-intensity light source is used, the depth of focus of the light beam incident on the near-field array head can be increased. This reduces kicking at the optical fiber core and further increases the coupling efficiency.

[Second Embodiment]
The exposure apparatus according to the second embodiment has the same configuration as the first embodiment except that the length of the optical fiber of the near-field array head is increased as shown in FIG. Parts are denoted by the same reference numerals and description thereof is omitted.

  The near-field array head 132A, except that the optical fiber 136A longer than the optical fiber 136 is used, is the same as the near-field array head 132 shown in FIG. The output side end portion 138 is provided. The incident end of the optical fiber 136A is fixedly arranged at a predetermined position so that the cores 140 are arranged in a matrix corresponding to the condensing position of the microlens array 130. On the other hand, the end 138 on the emission side of the optical fiber 136 </ b> A provided with the minute opening is disposed close to the surface of the photosensitive material 134 and is configured to be movable along the surface of the photosensitive material 134.

  In this exposure apparatus, when image data is input to a controller (not shown), the angle of the reflection surface of each micromirror of the DMD 110 is controlled based on the image data. The illumination light emitted from the light source 112 to the DMD 110 via the lens system 114 is reflected and modulated in a predetermined direction according to the angle of the reflection surface of each micromirror, and the modulated light is transmitted by the magnifying lens systems 126 and 128. It is enlarged and incident on each of the microlenses provided in the microlens array 130.

  The light collected by the microlens array 130 enters the corresponding cores arranged in a matrix on the near-field array head 132A and guides the light in the optical fiber 136A. Then, evanescent light oozes out from the minute opening formed at the exit side end of the optical fiber 136A, and the photosensitive material 134 is exposed with this evanescent light.

  As described above, in the present embodiment, since the incident end of the near-field array head is fixedly arranged at a predetermined position, as in the first embodiment, it is modulated by DMD and condensed by a microlens. Light can be efficiently incident on the corresponding optical fiber core. That is, using near-field light, high-precision digital exposure can be performed with high light utilization efficiency. Further, since the near-field array head having a long optical fiber is used, the spatial freedom of the output end of the near-field array head can be improved, and the near-field array head can be reduced in weight. . Further, the near-field array head can be positioned with ultra-high accuracy of nm, and fine control of the gap with the surface of the photosensitive material can be easily realized with ultra-high accuracy of nm. Furthermore, the near-field array head can be freely moved along the surface of the photosensitive material with ultrahigh accuracy.

[Third embodiment (reference example) ]
As shown in FIG. 7, the exposure apparatus according to the reference example has the same configuration as that of the first embodiment except that a near-field array head in which a light-shielding film and a minute opening are provided in a microlens array is used. Therefore, the same components are denoted by the same reference numerals and description thereof is omitted.

  The near-field array head 144 is disposed at a position where a DMD image is formed by the magnifying lens systems 126 and 128 and is disposed close to the surface of the photosensitive material 134. Further, as shown in FIGS. 8A and 8B, the near-field array head 144 includes a microlens array 146 in which microlenses are provided corresponding to the respective pixels of the DMD. A light shielding film 148 is provided on the surface of the microlens array 146 on the light emitting side, and a minute aperture 150 is provided at a condensing position of each microlens of the light shielding film 148. The diameter of the minute opening 150 is about 100 nm. When laser light is incident on the microlens array 146, evanescent light oozes out from the minute openings.

  The near-field array head 144 forms a light-shielding film 148 by depositing a metal thin film such as aluminum on the light exit surface of the microlens array 146, and makes a high-power laser beam incident on the microlens to make a microscopic aperture 150 at the focal position. Can be easily manufactured.

  In this exposure apparatus, when image data is input to a controller (not shown), the angle of the reflection surface of each micromirror of the DMD 110 is controlled based on the image data. The illumination light emitted from the light source 112 to the DMD 110 via the lens system 114 is reflected and modulated in a predetermined direction according to the angle of the reflection surface of each micromirror, and the modulated light is transmitted by the magnifying lens systems 126 and 128. The image is enlarged and incident on each of the microlenses provided in the microlens array 146 of the near-field array head 144. The light incident on the microlens array 146 is condensed in the vicinity of the minute opening 150 formed in the light shielding film 148. The evanescent light oozes out of the minute opening 150, and the photosensitive material 134 is exposed with this evanescent light.

  As described above, in the exposure apparatus according to the present embodiment, the microlens of the microlens array is arranged corresponding to each pixel portion of the DMD, and this microlens array is used as a part of the near field array head. Therefore, digital exposure can be performed with high accuracy and high light utilization efficiency using near-field light.

  Further, since the near-field array head composed of a microlens array that can be manufactured using a semiconductor process is used instead of the near-field array head using fibers, the pixel pitch can be made finer with higher accuracy. As a result, the number of arrays can be easily increased to 1 million pixels and 10 million pixels, and a near-field array head with higher resolution can be realized. Furthermore, since a semiconductor process can be used, it is possible to realize a near-field array head having a simple configuration, a small number of parts, and excellent mass productivity.

[Fourth Embodiment]
In the exposure apparatus according to the fourth embodiment, as shown in FIG. 9, light guided through a long optical fiber is incident on a near-field array head in which a microlens array is provided with a light-shielding film and a minute aperture. Since it is the same structure as 1st Embodiment except having set it as the structure made to carry out, the same code | symbol is attached | subjected to the same component and description is abbreviate | omitted.

  On the light emitting side of the microlens array 130, a light guide unit 152 configured by bundling a plurality of optical fibers is provided. At the incident end of the light guide unit 152, the cores of the optical fibers are arranged in a matrix corresponding to the condensing positions of the microlenses of the microlens array 130. A microlens array 154 is disposed on the light emitting side of the light guide unit 152.

  The incident end of the light guide unit 152 is fixedly arranged at a predetermined position so that the cores are arranged in a matrix corresponding to the condensing position of the microlens array 130. On the other hand, the output end of the light guide unit 152 is configured to be movable.

  Each microlens of the microlens array 154 is arranged in a matrix corresponding to the core of the optical fiber at the output end of the light guide unit 152. A near-field array head 144 shown in FIGS. 8A and 8B is disposed at a position where a DMD image is formed by the microlens array 154.

  In this exposure apparatus, when image data is input to a controller (not shown), the angle of the reflection surface of each micromirror of the DMD 110 is controlled based on the image data. The illumination light emitted from the light source 112 to the DMD 110 via the lens system 114 is reflected and modulated in a predetermined direction according to the angle of the reflection surface of each micromirror, and the modulated light is transmitted by the magnifying lens systems 126 and 128. It is enlarged and incident on each of the microlenses provided in the microlens array 130.

  The light collected by the microlens array 130 enters the optical fiber that constitutes the light guide unit 152, and is guided through the optical fiber and emitted. The light emitted from the light guide unit 152 is collected by each microlens of the microlens array 154 and is incident on each of the microlenses provided in the microlens array 146 of the near-field array head 144. The light incident on the microlens array 146 is condensed in the vicinity of the minute opening 150 formed in the light shielding film 148. The evanescent light oozes out of the minute opening 150, and the photosensitive material 134 is exposed with this evanescent light. In particular, when the pitch of the microlens array 146 is reduced, it is possible to increase the density by reducing the diameter of the light guide fiber by reducing the cladding diameter to about 10 μm.

  As described above, in the exposure apparatus of the present embodiment, the microlenses of the first microlens array are arranged corresponding to each pixel portion of the DMD, and the condensed beam of each microlens is guided to the fiber bundle. Since the third microlens array is used as the near field array head by the second microlens array in which the microlens is arranged corresponding to the focused beam, and the third microlens array is used as the nearfield array head, the nearfield light is It is possible to perform high-precision digital exposure with high light utilization efficiency.

  In this embodiment, the light condensed by the second microlens array is incident on the near-field array head constituted by the third microlens array provided with the light shielding film and the minute aperture in the vicinity of the condensing position. The exposure is performed with evanescent light that is brilliantly projected from the field array head, but the second microlens array may be provided with the light-shielding film and the minute aperture, and the second microlens array may be used as a near field array head. good.

  Further, since the near-field array head having a long optical fiber is used, the spatial freedom of the output end of the near-field array head can be improved, and the near-field array head can be reduced in weight. . Further, the near-field array head can be positioned with ultra-high accuracy of nm, and fine control of the gap with the surface of the photosensitive material can be easily realized with ultra-high accuracy of nm. Furthermore, the near-field array head can be freely moved along the surface of the photosensitive material with ultrahigh accuracy.

  Further, since the near-field array head composed of a microlens array that can be manufactured using a semiconductor process is used instead of the near-field array head using fibers, the pixel pitch can be made finer with higher accuracy. As a result, the number of arrays can be easily increased to 1 million pixels and 10 million pixels, and a near-field array head with higher resolution can be realized. Furthermore, since a semiconductor process can be used, it is possible to realize a near-field array head having a simple configuration, a small number of parts, and excellent mass productivity.

It is sectional drawing along the optical axis which shows the structure of the exposure apparatus which concerns on 1st Embodiment. It is a perspective view which shows the structure of the near-field array head used for the exposure apparatus shown in FIG. It is the elements on larger scale which show the structure of DMD. (A) And (B) is explanatory drawing for demonstrating operation | movement of DMD. (A) is a perspective view which shows the structure of a fiber array light source, (B) is a top view which shows the arrangement | sequence of the light emission point in the laser emission part of (A). It is sectional drawing along the optical axis which shows the structure of the exposure apparatus which concerns on 2nd Embodiment. It is sectional drawing along the optical axis which shows the structure of the exposure apparatus which concerns on 3rd Embodiment. (A) is a perspective view which shows the structure of the near-field array head used for the exposure apparatus shown in FIG. 1, (B) is sectional drawing along the optical axis of (A). It is sectional drawing along the optical axis which shows the structure of the exposure apparatus which concerns on 4th Embodiment. It is a top view which shows the structure of a combined laser light source. It is a top view which shows the structure of a laser module. It is a side view which shows the structure of the laser module shown in FIG. It is a partial side view which shows the structure of the laser module shown in FIG.

Explanation of symbols

110 Digital Micromirror Device (DMD)
112 Fiber array light source 114 Lens system 126, 128 Magnifying lens system 130, 154 Micro lens array 132, 132A, 144 Near-field array head 134 Photosensitive material 136, 136A Optical fiber 138 End 140 Core 142 Clad 146 Micro lens array 148 Light shielding film 150 Micro opening 152 Light guide part

Claims (4)

A light source that emits a light beam for illumination;
A spatial light modulation element that two-dimensionally arranges a plurality of pixel portions whose light modulation states change according to each control signal and modulates a light beam incident on the plurality of pixel portions from the light source for each pixel portion When,
A microlens array in which a plurality of microlenses are two-dimensionally arranged at a pitch corresponding to the plurality of pixel portions, and a light beam modulated by the pixel portions is collected for each microlens;
Each of the incident ends of a plurality of optical fibers each having a core and a clad formed in a taper shape at a pitch corresponding to the condensing position of the plurality of microlenses and having an emission end sharpened to a diameter of about several tens to several hundreds of nanometers Are two-dimensionally arranged head parts;
With
An exposure apparatus that exposes a photosensitive material with near-field light leaking from each of emission ends of the plurality of optical fibers.   The exposure apparatus according to claim 1, wherein the incident ends of the plurality of optical fibers are fixedly arranged and the exit ends of the plurality of optical fibers are movable. A light source that emits a light beam for illumination;
A spatial light modulation element that two-dimensionally arranges a plurality of pixel portions whose light modulation states change according to each control signal and modulates a light beam incident on the plurality of pixel portions from the light source for each pixel portion When,
A plurality of first microlenses are two-dimensionally arranged at a pitch corresponding to the plurality of pixel portions, and a light beam modulated by the pixel portions is collected for each of the first microlenses. A microlens array;
A light guide unit in which each of incident ends of a plurality of optical fibers is two-dimensionally arranged at a pitch corresponding to a condensing position of the plurality of first microlenses;
A plurality of second microlenses are two-dimensionally arranged at a pitch corresponding to the output end of the optical fiber, and a second light beam that is emitted from the optical fiber is collected for each second microlens. A microlens array of
A plurality of third microlenses are two-dimensionally arranged at a pitch corresponding to the condensing position of the plurality of second microlenses, and each light beam incident from the second microlens array is changed to the third microlens array. A third microlens array that collects light for each microlens,
A light-shielding film that is provided on the light exit surface of the third microlens array and in which each of the plurality of microscopic apertures is two-dimensionally arranged at a pitch corresponding to the light collection position of the plurality of third microlenses
With
An exposure apparatus that exposes a photosensitive material with near-field light leaking from each of the plurality of minute openings. The exposure apparatus according to any one of claims 1 to 3 , wherein a wavelength of the laser light is about 400 nm.

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