TW201333641A - Exposure optical system, exposure apparatus, and exposure method - Google Patents

Abstract

An exposure apparatus and an exposure method, which restrain a side lobe near a main beam using an aperture array by an aperture shape of a micro lens for performing high-precision exposure, are provided. A shading part 66b is disposed at an exit side of a micro lens 64a, so as to shift a position of a side lobe Bb near a focus position of the micro lens 64a. A main beam Ba is converged to about ψ 4 μ m before passing through a second aperture array 68. Also, the side lobe Bb is located within ψ 7.2 μ m from a center of the main beam Ba. A relative intensity of the side lobe Bb is restrained to be about 1/10 compared to the prior art. As a result of a laser light B narrowed by the second aperture array 68, the laser light B with a light intensity distribution is formed as if the side lobe Bb around the main beam Ba may be ignored.

Description

Exposure optical system, exposure device, and exposure method

The present invention relates to an exposure optical system, an exposure apparatus, and an exposure method, and more particularly to a hole array using a spatial light modulation element and a limiting aperture shape on a micro-lens emission side. An exposure optical system, an exposure device, and an exposure method of a micro-lens array.

An image exposure apparatus is known which includes an exposure head by which a desired pattern is exposed on a photosensitive material. The exposure head of the image exposure apparatus basically includes: a light source; a spatial light modulation element, a plurality of pixel parts each independently modulating light irradiated from the light source according to a control signal; and imaging optics In the system, an image formed by light modulated by the spatial light modulation element is imaged on the photosensitive material.

As an example of the configuration of the exposure head of the image exposure apparatus, the configuration includes a light source and a digital micromirror device (Digital Micro-mirror). Device, hereinafter referred to as "DMD"), as a light modulation element having a plurality of micro-mirrors; and a microlens array in which a plurality of light beams modulated by the plurality of micromirrors are arranged ( The light beam is a plurality of microlenses that are separately collected (for example, refer to Japanese Laid-Open Patent Publication No. 2004-1244).

According to the configuration using such a microlens array, even if exposed to a photosensitive material The size of the image on the material is enlarged, and the light beams from the respective pixel portions of the spatial light modulation element can also be collected by the respective microlenses of the microlens array, thereby having the following advantages, that is, on the photosensitive material. The pixel size of the exposed image (=spot size of each light) is narrowed and kept small, so that the definition of the image can be kept high.

The exposure head shown in Patent Document 1 is also on the exit side of the above-described microlens array There is an array of apertures in which a plurality of apertures for individually limiting the plurality of beams are individually arranged. By the action of the aperture array, each light beam is shaped such that the pixel size on the photosensitive material becomes a fixed size, and crosstalk between adjacent pixels is prevented.

However, as the image exposure device causes the brightness of the exposed image to be under Another factor of the drop is that there is a stray light generated from the spatial light modulation element or the peripheral light, and the stray light reaches the photosensitive material. As described in the above Patent Document 1, if one aperture array is provided for each microlens on the emission side of the microlens array, the stray light can be removed, and a high overall quenching ratio can be ensured. (The ratio of the amount of light when the pixel portion is in the on state and the pixel portion are all off), but there is a problem that the first portion is disposed on the emission side of the microlens array. The purpose of removing the stray light by the aperture array must be matched to the beams that are concentrated by the microlens array. The diameter of the imaging component is extremely tightly defined by the size of each aperture and the position of the first aperture array, making it difficult to adjust and maintain the alignment.

An object of the present invention is to provide an exposure optical system, an exposure apparatus, and an exposure method in consideration of the above-described facts, and suppressing side lobes around a main beam by an aperture array by an aperture shape of a microlens (side) Lobe) for high-definition exposure.

A first embodiment of the present invention provides an exposure optical system including: a spatial light modulation element in which a pixel portion for modulating light from a light source is arranged; and a microlens array in which the spatial light modulation element is arranged a modulated microlens that condenses light; a first aperture array having an aperture shape that restricts transmission of light on an emission side of the microlens; a mask, and an optical axis of the microlens ( The light axis is provided at the aperture portion of the first aperture array, the outer shape of the mask is similar to the aperture shape of the aperture portion, and the mask shields light transmitted through the aperture portion; the first imaging optics a system for imaging light modulated by the spatial light modulation element on the microlens array; a second imaging optical system for imaging light collected by the microlens array on a photosensitive material; and a second aperture The array has apertures that narrow the light emitted from each of the microlens arrays at a condensing position of the microlens array.

According to the above aspect of the invention, the excess light (side lobes) of the beam narrowed by the second aperture array can be obtained by the mask provided in the first aperture array. The aperture diameter of the second aperture array is also large and diffused, whereby the excess light can be efficiently cut.

A second embodiment of the present invention provides an exposure optical system having a transmissive portion similar to the mask at a center of the mask, centering on an optical axis of the microlens.

According to the above invention, the portion including the optical axis as the center of the mask is set as the transmission portion, whereby the excess light can be efficiently reduced without lowering the amount of light of the main beam.

According to a third aspect of the invention, there is provided an exposure optical system, wherein the mask is a concentric annular shape centering on an optical axis of the microlens.

According to the above invention, the exposure optical system can be formed such that when the shape of the microlens is a circle centered on the optical axis, the light beam having a small amount of light distribution with respect to the circumferential direction is exposed.

A fourth embodiment of the present invention provides an exposure optical system, wherein the mask is a concentric rectangular shape centering on an optical axis of the microlens.

According to the above invention, the exposure optical system can be formed such that when the shape of the microlens is a rectangle centered on the optical axis, the light beam having a small amount of light is exposed to light exposure.

According to a fifth aspect of the invention, there is provided an exposure optical system, wherein the light shielding portion and the transmission portion include an opaque portion and a transparent portion of a film attached to an emission side of the microlens.

According to the above invention, a part of the transparent film is made opaque to form a mask, whereby accurate masking can be performed with less man-hours.

A sixth embodiment of the present invention provides an exposure optical system, wherein The mask is a chrome mask formed on the exit side of the microlens.

According to the above invention, the mask is formed by the light shielding film containing chromium, whereby the shape can be shaped An exposure optical system having a mask that has less leakage and can attain a higher optical density.

A seventh embodiment of the present invention provides an exposure optical system, wherein The outer peripheral portion of the aperture portion of the first aperture array is an opaque portion.

According to the above invention, the outer peripheral portion of the aperture portion is an opaque shading portion In this way, the shape of the transmissive portion of the microlens can be defined by the mask, and the number of parts and the number of man-hours can be reduced.

An eighth embodiment of the present invention provides an exposure optical system, wherein The above light source is a semiconductor diode (LD).

According to the above invention, it is easy to control by using monochromatic laser light Exposure optical system with light quantity distribution, high reliability and high illumination.

A ninth embodiment of the present invention provides an exposure optical system, comprising: a lens that condenses light from a light source, a first aperture having an aperture shape that restricts transmission of light on an emission side of the lens, and a mask that is disposed around an optical axis of the lens In the aperture portion of the first aperture, the outer shape of the mask is similar to the aperture shape of the aperture portion, the mask shields light transmitted through the aperture portion, and the first imaging optical system images the light a second imaging optical system that images light collected by the lens on a photosensitive material; and a second aperture, and an aperture that narrows light emitted from the lens at a condensing position of the lens .

According to the above invention, the mask is provided in the first aperture, so that the second The excess light (side lobes) of the light beam whose aperture is narrowed is diffused larger than the diameter of the second aperture, whereby the excess light can be efficiently reduced.

A tenth embodiment of the present invention provides an exposure apparatus using the first In the exposure optical system according to any one of the ninth embodiments, the specific pattern is exposed to the photosensitive material.

According to the above invention, by the mask, the second aperture array or aperture is The excess light (side lobes) of the narrowed beam is diffused larger than the diameter of the second aperture, whereby the excess light can be efficiently reduced without lowering the amount of light of the main beam.

An eleventh embodiment of the present invention provides an exposure method using the tenth The exposure apparatus provided in the embodiment exposes a specific pattern to the photosensitive material.

According to the above invention, by the mask, the second aperture array or aperture is The excess light (side lobes) of the narrowed beam is diffused larger than the diameter of the second aperture, whereby the excess light can be efficiently reduced without lowering the amount of light of the main beam.

Since the present invention is formed as described above, it is possible to suppress the side lobes around the main beam by the aperture array by the aperture shape of the microlens, thereby enabling high-definition exposure.

10‧‧‧Exposure device

14‧‧‧Mobile platform

16‧‧‧foot

18‧‧‧Setting table

20‧‧‧rails

22‧‧‧ gate

24‧‧‧ Scanner

26‧‧‧Sensor

28‧‧‧Exposure head

30‧‧‧Exposure area

31‧‧‧Exposured areas

34‧‧‧DMD

52‧‧‧1st imaging optical system

52A, 52B, 58A, 58B‧‧ lens

58‧‧‧2nd imaging optical system

64a‧‧‧microlens

64‧‧‧Microlens array

66‧‧‧1st aperture array

66a‧‧‧Aperture Department

66b‧‧‧Lighting Department

66c‧‧‧through section

68‧‧‧2nd aperture array

72‧‧‧SRAM

74‧‧‧Micromirror

B‧‧‧Laser light

Ba‧‧‧ main beam

Bb‧‧‧ side lobes

P‧‧‧Photosensitive materials

FIG. 1 is a conceptual diagram showing a main part of an exposure apparatus according to an embodiment of the present invention.

Fig. 2 is a perspective view showing a main part of an exposure head according to an embodiment of the present invention.

3 is a perspective view showing an example of a DMD according to an embodiment of the present invention.

4A to 4B are perspective views showing a switch (on/off) state of a DMD according to an embodiment of the present invention.

FIG. 5 is a conceptual diagram showing an optical system arrangement after the DMD according to the embodiment of the present invention.

6A to 6B are conceptual views showing a light amount distribution of a condensing position of a conventional microlens.

Fig. 7 is a conceptual diagram showing the cause of the deviation of the optical system according to the embodiment of the present invention.

8A to 8B are conceptual diagrams showing the relationship between the first first aperture array and the light amount distribution.

9A to 9B are conceptual diagrams showing the relationship between the first aperture array and the light amount distribution according to the embodiment of the present invention.

10A to 10C are conceptual diagrams showing the relationship between the first aperture array, the light amount distribution, and the second aperture array and the light amount distribution according to the embodiment of the present invention.

Fig. 11 is a conceptual diagram showing the influence of the first aperture array on the light amount distribution according to the embodiment of the present invention.

Fig. 12 is a conceptual diagram showing an aperture shape of a first aperture array according to another embodiment of the present invention.

FIG. 13 is a conceptual diagram and a numerical expression showing the relationship between the aperture shape of the first aperture array and the light intensity on the focal plane of the microlens according to the embodiment of the present invention.

14 is a conceptual diagram and a numerical expression showing the relationship between the aperture shape of the first aperture array and the light intensity on the focal plane of the microlens according to the embodiment of the present invention.

Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings.

<Overall composition>

As shown in FIGS. 1 and 2, the exposure apparatus 10 of the present embodiment includes a flat-shaped moving stage 14 that adsorbs and holds a sheet-shaped photosensitive material P on the surface. On the upper surface of the thick plate-shaped mounting table 18 supported by a plurality of (for example, four) leg portions 16, two guides 20 extending in the direction in which the platform moves are provided. The moving platform 14 is disposed in such a manner that its longitudinal direction faces the direction in which the platform moves, and can be supported to reciprocate along the guide rail 20. Further, the exposure apparatus 10 is provided with a stage driving device (not shown), and drives the moving platform 14 as a sub-scanning mechanism along the guide rail 20.

A gate 22 having a bridge shape is provided at a central portion of the installation table 18 so as to straddle the movement path of the moving platform 14. Each end of the shutter 22 is fixed to each of the faces on both sides of the installation table 18. A scanner 24 is disposed on one side of the shutter 22, and a plurality of (for example, two) sensors 26 for detecting the front end and the rear end of the photosensitive material P are disposed on the other side. The scanner 24 and the sensor 26 are respectively mounted on the shutter 22 and fixedly disposed upstream of the moving path of the moving platform 14. Further, the scanner 24 and the sensor 26 are connected to a controller (not shown) that controls these.

As an example, the scanner 24 includes a plurality of (14 in the drawing) exposure heads 28 arranged in a matrix of m rows and n rows. The exposure area 30 of each exposure head 28 is a rectangular shape in which the sub-scanning direction is a short side. Thus, as the moving platform 14 moves, each of the exposure heads 28 forms a strip-shaped exposed area 31 on the photosensitive material P.

The plurality of exposure heads 28 include a light source (for example, a semiconductor laser (LD) or the like) not shown, and emits, for example, laser light having a wavelength of 400 nm; and, for example, the DMD 34 shown in FIG. Data (data) for each pixel A spatial light modulation element that is modulated by laser light emitted from a light source. The DMD 34 is connected to a controller (not shown) including a data processing unit and a mirror drive control unit. A data processing unit of the controller generates a control signal for driving control of each of the micromirrors 74 (which will be described later) in the use region on the DMD 34 based on the input image data. Further, in the mirror drive control unit, the angle of the reflection surface of each of the micromirrors 74 of the DMD 34 is controlled for each of the exposure heads 28 based on the control signal generated by the image data processing unit.

The optical system after the DMD 34 is shown in a conceptual diagram in FIG. to The light reflecting side (the exit side and the exit side) of the DMD 34 is provided with a main optical system, and the laser light B reflected by the DMD 34 is formed on the photosensitive material P. The primary optical system includes: a first imaging optical system 52 that amplifies a light beam modulated by the DMD 34; a second imaging optical system 58 that images a light beam on the photosensitive material P; and a microlens array 64 into which the imaging optical system is inserted The first aperture array 66 is disposed near the exit side of the microlens array 64, and the second aperture array 68 is disposed at a focus position of the microlens array 64.

The first imaging optical system 52 includes, for example, a lens 52A on the incident side, The lens 52B on the exit side; the DMD 34 is disposed on the focal plane of the lens 52A. The lens 52A coincides with the focal plane of the lens 52B, and the microlens array 64 is disposed on the focal plane of the exit side of the lens 52B. Further, the second imaging optical system 58 also includes, for example, a lens 58A on the incident side, a lens 58B on the exit side, a focal plane surface of the lens 58A and the lens 58B, and a microlens array 64 in which the second aperture array 68 is disposed. The focus position is the focal plane of the lens 58A. A photosensitive material P is disposed on a focal plane of the exit side of the lens 58B.

The first imaging optical system 52 amplifies the image formed by the DMD 34, Imaging is performed on the microlens array 64. Further, the second imaging optical system 58 images and projects the image passing through the microlens array 64 on the photosensitive material P. Further, each of the first imaging optical system 52 and the second imaging optical system 58 emits a plurality of light beams from the DMD 34 as light beams that are substantially parallel to each other.

As shown in FIG. 3, the DMD 34 used in the present embodiment is: Yu Jing On a random random access memory (SRAM) cell (memory cell) 72, a plurality of pixels (for example, 1024×768) are arranged in a lattice. A mirror device of a micromirror (micromirror 74). In each of the pixels, a rectangular micromirror 74 supported by a pillar is provided on the uppermost portion, and a material having a high reflectance such as aluminum is deposited on the surface of the micromirror 74.

If a digital letter is written in the SRAM cell 72 of the DMD 34 In other words, each of the micromirrors 74 supported by the pillars is inclined at any angle of ±α degrees with respect to the substrate side on which the DMD 34 is disposed, centering on the diagonal. 4(A) shows a state in which the micromirror 74 is tilted by +α° in an on state, and FIG. 4(B) shows a state in which the micromirror 74 is in an off state and tilted by -α°. Therefore, by the inclination of the micromirrors 74 in the respective pixels of the DMD 34 as shown in FIG. 4 in accordance with the image signal, the laser light B incident on the DMD 34 is reflected toward the oblique direction of each of the micromirrors 74.

In addition, in FIG. 4, a part of the DMD 34 (one micromirror) is shown. Partially an example of a state in which the micromirror 74 is controlled to be +α° or -α°. The on/off control of each of the micromirrors 74 is performed by a controller (not shown) connected to the DMD 34.

<Microlens array>

The microlens array 64 is: corresponding to each micromirror 74 on the DMD 34 The microlenses 64a are arranged, for example, in a two-dimensional shape of, for example, 1024 × 768 or so. In the present embodiment, as an example, each of the microlenses 64a is a plano-convex lens in which the incident surface is a flat surface and the emission surface is a convex surface, and a plano-convex lens made of quartz glass having a focal length of 100 μm is used. Further, it is not limited to the above examples, and a biconvex lens or the like may be used. Further, the microlenses 64a and the connecting portions connecting the microlenses 64a in an array shape may be integrally formed by the same material to form the microlens array 64, or the microlenses 64a may be embedded and provided. Each of the micro mirrors 74 has a plurality of apertures in the respective apertures of the base plate.

The first aperture array 66 and the second aperture array 68 are: An array of a plurality of apertures corresponding to the respective microlenses 64a, the first aperture array 66 is disposed adjacent to the exit side of the microlens array 64 (may also be attached to the microlens 64a), and the second aperture array 68 is coupled to the microlens array 64. They are spaced apart in space.

In this embodiment, the first aperture array 66 may also be: a microlens A portion other than the aperture portion on the exit side surface of 64a is provided with a chrome cover (a light-shielding film containing chromium) or a transparent/semi-transmissive coating to form an array of masks, or may be in direct contact. An array of light shielding films is disposed on the transparent mask in the vicinity of the exit surface of the microlens 64a. As an example, the second aperture array 68 is configured by applying a light-shielding film containing chromium, for example, to a transparent supporting member including quartz glass.

<main beam and excess light>

As described above, in the image exposure apparatus of the present aspect, by the microlens The side lobe generated at the periphery of the concentrated main beam is a factor that causes the sharpness of the exposed image to decrease. The side lobes are not only generated by the optical system aberration upstream of the microlens containing the light modulation element, but also due to the existence of the microlens aperture itself. Generated rationally. Hereinafter, a process of generating side lobes caused by the microlens aperture and a method of mitigating side lobes will be described.

The aperture shape of the first aperture array 66 is a simple shape (for example, a circle In the case of the shape, the light intensity distribution near the focal position of the microlens 64a shown by R in Fig. 6A is generally Fourier transform (Fourier transform) of the aperture shape of the first aperture array 66 as shown in Fig. 6B. And the distribution. At this time, excess light (side lobes Bb) having a smaller intensity than the main beam Ba is generated around the main beam Ba (center) having a strong light intensity.

In addition to the examples shown in FIGS. 6A to 6B, a first aperture is also considered. In any case, such as the case where the aperture shape of the array 66 is rectangular, in any case, the light intensity distribution in the vicinity of the focal position of the microlens 64a becomes the Fourier transform of the aperture shape of the first aperture array 66. The positional relationship and intensity ratio of the main beam Ba and the side lobes Bb are generally specified when the aperture size of the first aperture array 66 and the focal length of the microlens 64a and the wavelength of the laser light B are defined.

Hereinafter, the aperture shape of the first aperture array 66 will be described with reference to FIGS. 13 and 14. The relationship between the light intensity of the focal plane of the microlens 64a will be described.

As shown in FIG. 13, a function indicating the shape of the first aperture array 66 will be used. When V (ξ, η) is set, V (ξ, η) = 1 (inside the aperture, no mask), V (ξ, η) = 0 (outside of the aperture, masking), and the focal plane of the microlens 64a (x) The intensity of the light of y) is the Fourier transform of the aperture shape of the first aperture array 66 as shown in Equation 1 of FIG.

At this time, if the aperture shape of the first aperture array 66 is circular, it can be simplified. Formula 1 above. In other words, when the distance from the z-axis (optical axis) of the aperture surface of the microlens 64a is R and the radius of the aperture is Rmax, V(R)=1(|R |<Rmax), V(R) = 0 (| R | >Rmax); when the distance of the focal plane of the microlens 64a (= the second aperture array 68) from the z-axis is set, the light intensity is | U(r)| 2 The light intensity of the focal plane is as shown in Equation 2.

Here, as shown in FIG. 14, it is considered that the microlens 64a is as in the present embodiment. The aperture face is provided with n annular apertures having a shape similar to the aperture shape (Rmax). When the transmittance in Rm-1≦R≦Rm is Tm (fixed), the light intensity of the focal plane is as shown in Formula 3.

Thus, by appropriately setting {R1...Rn} (radius of the aperture) and {T1...Tn} (transmittance), the side lobes Bb (excess light) shown in FIG. 6B can be made on the second aperture array 68, which is the focal plane of the microlens 64a, from the optical axis (z-axis) to the outside. Moving, the second aperture array 68 can be utilized to remove excess light. When {T1...Tn} is set to a complex number, it is possible to improve not only the transmittance change but also the effect of changing the phase component of the light to improve the side lobes.

That is, when T1=1 (transmission), T2=0 (masking), T3=1 (transmission), and the focal length f of the microlens 64a is set to 100 μm, as shown in FIG. 9A, as R0=0, (R1/f)=0.09535 (radius R1=9.535 μm, 1=19.07 μm), (R2/f)=0.1277 (R2=12.77 μm, 2=25.54 μm), (R3/f)=0.15 (R3=15 μm, In the same manner as 3 = 30 μm, the respective sizes of the aperture portion 66a, the light shielding portion 66b, and the transmission portion 66c of the first aperture array 66 are derived. These numerical values are values derived from the above mathematical expressions, and are different from the optical system having a circular aperture in the prior art in terms of purpose, establishment conditions, and the like.

This embodiment is an example of sidelobe reduction caused by the microlens aperture, but even For the side lobes caused by the axial contrast aberration caused by the optical system upstream of the microlens, such as a light modulation element such as DMD, it is also possible to appropriately select {R1...Rn} (light) The radius of the circle) and {T1...Tn} can alleviate the influence of the aperture while reducing the influence of the side lobes.

On the other hand, for the following reasons, it is desirable to suppress as much as possible. The relative intensity ratio of the side lobe Bb portion with respect to the main beam Ba. That is, in general, when exposed to a high-sensitivity sensitive material, there is a possibility that the sensitized material is photosensitive (atomized) due to the side lobe light Bb, and the effective line width becomes thick (the resolution is lowered). Further, when high-definition exposure is performed by an exposure apparatus using a two-dimensional optical modulation element like the DMD 34, the adjacent drawing beams are spaced apart, so that the light intensity distribution of the ON beam (during drawing) is wide (the laser light B becomes thick). The influence of the sidelobe Bb that becomes a factor affecting the adjacent drawing line cannot be ignored.

In view of this, if the focus position disposed on the microlens array 64 can be attached It is preferable that the aperture of the second aperture array 68 is sufficiently small to retain the main beam Ba and remove only the side lobe Bb. However, for the following reasons, it is difficult to accurately remove only the side lobe Bb component.

That is, as shown in FIG. 7, each microlens 64a has a manufacturing variation. The optical axis of the lens is deviated from the center of each aperture of the second aperture array 68. Further, due to manufacturing variations (telemetric deviation) of the first imaging optical system 52 and the second imaging optical system 58, the position of the main beam Ba emitted from each of the microlenses 64a is generated from the respective apertures of the second aperture array 68. The center is shifted in parallel. Therefore, there is a concern that the center of the aperture of the aperture array 68 deviates from the center of the main beam Ba, and the main beam Ba is narrowed to cause insufficient light.

For the reasons described above, the second aperture array 68 is utilized for the side lobes Bb When the diameter of the aperture of the second aperture array 68 is reduced and the entire laser beam B is narrowed, a part of the main beam Ba is also subjected to the second. The aperture array 68 is cut, and a problem of intensity unevenness (mura) between the condensed beams of the respective microlenses 64a occurs.

Therefore, in the present embodiment, the first aperture array 66 is provided with a hole. The diameter of the mask is a similar shape, and the laser light B is narrowed, whereby the position of the side lobe Bb at the focus position of the microlens array 64 is deviated from the direction in which the autonomous beam Ba leaves (the direction away from the optical axis). When the second aperture array 68 is used to narrow the light other than the main beam Ba, the main beam Ba can be retained and the side lobes Bb can be effectively reduced. The drawing line can be kept thin while being exposed while preventing the adjacent line. The crosstalk between the beams can prevent the amount of light from dropping.

Hereinafter, a model description will be made using FIGS. 8 to 11 . Here, In the lens surface of the microlens array 64 (microlens 64a), the light shielding portion 66b is provided with a chrome cover or the like, and the first aperture array 66 is set. However, in order to improve the light use efficiency, it is also possible to The lens 64a is realized by providing a transparent/translucent coating. Further, the first aperture array 66 may not be directly applied to the lens exit surface, but may be separately applied to the vicinity of the lens exit surface. The configuration of the mask described here is merely a representative example, and the number of the rings of the light-shielding portion 66b described below or the like may be increased.

In the previous configuration shown in FIG. 8A, the focus position on the microlens 64a In the vicinity, the relative intensity and positional relationship between the main beam Ba and the side lobes Bb become as shown in Fig. 8B. In other words, the side lobes Bb exist in the range of about 4 μm from the center of the autonomous beam Ba, which causes various problems as described above.

In the embodiment shown in FIG. 9A, by the shot on the microlens 64a The light blocking portion 66b is provided on the exit side, and the position of the side lobe Bb near the focus position of the microlens 64a is moved.

The light shielding portion 66b is in the aperture portion 66a of the first aperture array 66, An array of the light shielding portions 66b similar to the aperture portion 66a is provided. If the aperture portion 66a is circular, the light shielding portion 66b is also circular in shape similar to the aperture portion 66a, as shown in FIG. 9A. Further, a transmissive portion 66c similar in shape to the aperture portion 66a may be further provided. The presence of the transmissive portion 66c is not essential, but in order to effectively utilize the amount of light of the laser light B (main beam Ba), it is preferable that the transmissive portion 66c is present.

Specifically, the microlens 64a is a plano-convex lens having a focal length of 100 μm, and the aperture portion 66a is set to 30 μm, the outer diameter of the light shielding portion 66b is set to 25.54 μm, set the diameter of the through portion 66c to 19.07 μm and use laser light with a wavelength of λ = 400 nm.

As shown in FIG. 9 to FIG. 11, in this mode example, the amplitude of the main beam Ba is 4 μm, making the center of the sidelobe Bb autonomous beam Ba 7.2 μm, compared with the previous one, the suppression is 1/10, and the aperture diameter of the second aperture array 68 is set to 5.6 μm. According to this configuration, even when the center of the main beam Ba and the aperture center of the second aperture array 66 are deviated by, for example, ±0.8 μm due to the influence of the manufacturing variation, the second aperture array 68 can be excellently accurate. The side lobes Bb are suppressed.

That is, the light intensity distribution of the laser light B in the arrangement of the microlens 64a and the first aperture array 66 (the aperture portion 66a and the light shielding portion 66b) as shown in FIG. 10A is as shown in the figure before passing through the second aperture array 68. As shown in 10B, the main beam Ba converges on 4 μm or so, and the sidelobe Bb is at the center of the autonomous beam Ba. The range of 7.2 μm is suppressed to about 1/10 in relative strength as compared with the previous example shown in Fig. 8 (Fig. 11).

With the second aperture array 68 ( 5.6 μm) As a result of narrowing the laser light B of such a light intensity distribution, as shown in FIG. 10C and FIG. 11, the laser light having a light intensity distribution like the side lobe Bb around the main beam Ba can be ignored. B.

Further, the intensity of the side lobes Bb is suppressed to a range of about 1/10 of the relative strength as compared with the previous example. 7.2 μm, in contrast, the aperture diameter of the second aperture array 68 is 5.6 μm, even if the axial misalignment between the optical axis and the second aperture array 68 due to manufacturing variations of the microlens 64a and the manufacturing variation of the first imaging optical system 52 are inconsistent as described above, The deviation of the condensing position is ±0.8 μm, and the second aperture array 68 can also remove only the side lobes Bb with high precision.

<Shape of shading>

In the above embodiment, the case where the aperture shape of the first aperture array 66 is circular is exemplified, but the present invention is not limited thereto, and the present invention can be applied to other shapes.

In other words, as shown in FIG. 12, when the aperture shape of the first aperture array 66 is rectangular, the light-shielding portion 66b can be rectangular again, and the position of the side lobe Bb at the focus position of the microlens 64a can be made autonomous. The place where the beam Ba leaves is offset. Moreover, when the transmission portion 66c is provided in the center of the light shielding portion 66b, the shape is similar to the aperture shape.

Further, the light shielding portion 66b does not have to be a member that completely shields the laser light B, and the light shielding portion 66b having a rotationally symmetrical shape may have a gradient (gradation) and the laser light B may be stepwise. Through the parts. In addition to this, an element having a specific optical density such as a neutral density filter (ND filter) may be used as the light shielding portion 66b.

<Other>

The embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit and scope of the invention.

For example, in the above embodiment, the exposure exposed by laser light is listed. The configuration of the optical device is an example, but is not limited thereto. For example, ordinary visible light, ultraviolet light, or the like can be used. Alternatively, in addition to the exposure device, it can be applied to various configurations using spot light.

Moreover, in the present embodiment, a spatial modulation element as a reflection type is used. The DMD 34 has been described, but it is also possible to use, for example, a transmissive spatial modulation element using liquid crystal instead of the DMD 34.

The entire disclosure of Japanese Patent Application No. 2012-011050, by reference It is introduced in this specification. All documents, patent applications, and technical standards described in the present specification are incorporated by reference to the same extent as individually and individually by reference to the disclosure of individual documents, patent applications, and technical standards. In the manual.

64a‧‧‧microlens

66a‧‧‧Aperture Department

66b‧‧‧Lighting Department

68‧‧‧2nd aperture array

B‧‧‧Laser light

Ba‧‧‧ main beam

Bb‧‧‧ side lobes

Claims (11)

An exposure optical system comprising: a spatial light modulation element arranged with a pixel portion for modulating light from a light source; and a microlens array arranged to condense light modulated by the spatial light modulation element a microlens; the first aperture array has an aperture portion having an aperture shape that restricts transmission of light on an emission side of the microlens; and the mask is provided on the first aperture array around the optical axis of the microlens In the aperture portion, the outer shape of the mask is similar to the aperture shape of the aperture portion, the mask shields light transmitted through the aperture portion, and the first imaging optical system modulates light modulated by the spatial light modulation element Imaging the microlens array; the second imaging optical system images the light collected by the microlens array on the photosensitive material; and the second aperture array is arranged at the condensing position of the microlens array The apertures emitted by the respective light beams of the microlens array are narrowed. The exposure optical system according to claim 1, wherein the optical axis of the microlens is centered, and a transmissive portion having a shape similar to that of the mask is provided at a center of the mask. The exposure optical system according to claim 2, wherein the mask is a concentric annular shape centering on an optical axis of the microlens. The exposure optical system according to claim 2, wherein the mask is a concentric rectangular shape centering on an optical axis of the microlens. The exposure optical system according to any one of the second aspect, wherein the mask and the transmissive portion include an opaque portion and a transparent portion of a film attached to an emission side of the microlens . The exposure optical system according to any one of the items 1 to 4, wherein the mask is a chrome cover formed on the output side of the microlens. The exposure optical system according to any one of claims 1 to 6, wherein the outer peripheral portion of the aperture portion of the first aperture array is an opaque portion. The exposure optical system according to any one of claims 1 to 7, wherein the light source is a semiconductor laser. An exposure optical system comprising: a lens for collecting light from a light source; a first aperture, an aperture portion having an aperture shape that restricts transmission of light on an emission side of the lens; and a mask having an optical axis of the lens The aperture portion provided in the first aperture, the outer shape of the mask is similar to the aperture shape of the aperture portion, the mask shields light transmitted through the aperture portion, and the first imaging optical system transmits the light Imaged on the lens; the second imaging optical system images the light collected by the lens on the photosensitive material; and the second aperture is narrowed at the condensing position of the lens to illuminate the light emitted from the lens Aperture. An exposure apparatus comprising: using an image exposure as described in any one of claims 1 to 9 A light optical system that exposes a specific pattern to a photosensitive material. An exposure method comprising: exposing a specific pattern to a photosensitive material using an image exposure apparatus as described in claim 10 of the patent application.