JP2003177336A - Optical modulating element, optical modulating element array, and exposure device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-output and long-life optical modulating element which absorbs less light by itself and can be driven fast, an optical modulating element array, and an exposure device using it. <P>SOLUTION: The optical modulating element 100 which varies the quantity of light transmitted through a movable thin film 27 by displacing the movable thin film 27 over a plane substrate 23 with an electrostatic force is characterized by that the movable thin film 27 is formed rectangularly and supported at both lengthwise ends, a movable thin film non-electrode part 41 which does not have no plane electrode is formed at the lengthwise center part of the movable thin film 27, and a substrate-side non-electrode part 43 which has no plane electrode is formed at a position facing the movable thin film side non-electrode part 41 on the plane substrate 23. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light modulation element and a light modulation element array for modulating light by displacing the movable thin film by electrostatic force to change the amount of light transmitted or reflected by the movable thin film. An exposure apparatus using the same.

[0002]

2. Description of the Related Art An optical modulator is a control element that temporally changes the amplitude, phase, and frequency of light. The light modulation element changes the refractive index of a substance that transmits light according to an external field applied to the substance, and finally transmits or reflects this substance through optical phenomena such as refraction, diffraction, absorption, and scattering. Control the intensity of light. As one of them, an electromechanical light modulation element is known in which a movable thin film produced by micromachining is mechanically operated by electrostatic force to perform light modulation. As the light modulation element, for example, as shown in FIG. 17, one in which a movable thin film 5 composed of a transparent electrode 1 and a diaphragm 3 is laid on a flat substrate 11 having a fixed electrode 9 via a support portion 7 is used. is there.

In this light modulating element, an electrostatic force is generated between the electrodes 1 and 9 by applying a predetermined voltage between the electrodes 1 and 9 to bend the movable thin film 5 toward the fixed electrode 9.
Along with this, the optical characteristics of the element itself change (for example, the intensity of the light emitted from the light modulator is controlled by using Fabry-Perot interference), and the light modulator is in a transmissive state in which light is transmitted. On the other hand, by setting the applied voltage to zero, the movable thin film 5
Is elastically restored, and the light modulation element enters a light blocking state that blocks light. Light modulation is performed in this way. According to this type of optical modulator, the movable thin film 5 is driven by electrostatic induction, so that a faster response is possible compared to the conventional liquid crystal optical modulator.

[0004]

In the above-mentioned conventional optical modulator, a transparent conductive film is generally provided on the entire surface of the overlapping portion of the movable thin film and the flat substrate in order to generate an electrostatic force in the movable thin film. . However, the conductivity of the transparent conductive film is smaller than that of metal by about two digits. Therefore, the electrostatic force cannot be generated with good responsiveness, which is an obstacle to high-speed driving. Further, since it absorbs a slight amount of light, there is a problem that when the light intensity is high, the transparent conductive film generates heat and is deformed or destroyed.
Meanwhile, KWGoossen, et al., IEEE Photonics Tech. Let
ters Vol.6, No.9, P.1119, (1994). discloses the structure of a light modulation element in which an electrode is not provided in the light transmission part of the movable thin film, but this structure is used for reflection. In addition, the flat substrate is opaque and cannot be used for light modulation by transmission. Further, in this light modulation element, since the movable thin film is formed in a square shape and the electrodes are arranged on the four sides thereof, when a plurality of light modulation elements are arranged in one dimension or two dimensions, the light transmission of the adjacent light modulation elements is reduced. Since two electrodes are interposed between the parts, there is a problem that the pixel becomes rough when used in an exposure device, a display device, or the like.

The present invention has been made in view of the above circumstances, and has a high output and long life optical modulator and optical modulator array, in which light absorption by the element itself is small, and which can be driven at high speed, and an exposure apparatus using the same. The purpose is to provide.

[0006]

In order to achieve the above object, the electrostatic drive element according to claim 1 of the present invention is characterized in that the movable thin films are arranged facing each other with a space on a flat substrate, and Flat electrodes are provided on both of the movable thin films, and the movable thin film is displaced with respect to the flat substrate by an electrostatic force generated by applying a voltage to each of the flat electrodes to change the amount of light transmitted through the movable thin films. In the light modulation element, the movable thin film is formed in a rectangular shape and is supported at both ends in the longitudinal direction, and a movable thin film side non-electrode portion having no planar electrode is formed at a central portion in the longitudinal direction of the movable thin film. The planar substrate is characterized in that a substrate-side non-electrode portion having no planar electrode is formed at a position facing the movable thin film-side non-electrode portion.

In this light modulating element, the movable thin film is formed in a rectangular shape, and the movable thin film side non-electrode portion in which no electrode is formed is provided at the central portion in the longitudinal direction of the movable thin film. By providing the substrate-side non-electrode portion facing the non-electrode portion, it is not necessary to provide the transparent electrode in the light-transmitting portion of the movable thin film and the flat substrate, so that light absorption by the transparent electrode can be eliminated. As a result, it is possible to prevent deformation and destruction of the transparent electrode due to heat generation when the light intensity is high, and it is possible to realize high output and long life. Further, the simplified structure of the movable thin film enables high speed driving of the light modulation element.

According to a second aspect of the present invention, there is provided a light modulation element, in which a movable thin film is opposed to a planar substrate with a space therebetween, and planar electrodes are provided on both the substrate and the movable thin film, and a voltage to each planar electrode is applied. A reflective light modulation element that displaces the movable thin film with respect to the flat substrate by an electrostatic force generated by application and changes the amount of light reflected by the movable thin film, wherein the movable thin film is formed in a rectangular shape. A movable thin film side non-electrode portion, which is supported by both ends in the longitudinal direction and has no planar electrode, is formed at the central portion in the longitudinal direction of the movable thin film.

In this light modulating element, the movable thin film is formed in a rectangular shape, and the non-electrode portion on the movable thin film side where no electrode is formed is provided in the central portion in the longitudinal direction of the movable thin film, so that the light reflecting portion of the movable thin film is transparent. Since it is not necessary to provide an electrode, absorption of light by the transparent electrode can be eliminated. As a result, it is possible to prevent deformation and destruction of the transparent electrode due to heat generation when the light intensity is high, and it is possible to realize high output and long life. Further, the simplified structure of the movable thin film enables high speed driving of the light modulation element.

In the light modulator according to the first and second aspects, if the incident light is applied to a part or the whole of the region of the movable thin film side non-electrode part, the movable thin film without electrodes. Since the incident light is radiated onto a part or the whole area of the side non-electrode portion, it is possible to obtain a structure with improved light utilization efficiency. Further, if the movable thin film is displaced by applying a voltage to the planar electrode for optical modulation of the optical modulators according to the first and second aspects, an optical interference effect can be generated. In this light modulation element, when a voltage is applied to the electrode of the movable thin film and the electrode of the flat substrate, the movable thin film is displaced by the electrostatic force acting between the electrode of the movable thin film and the electrode of the flat substrate. In this case, for example, in the case of Fabry-Perot interference, reflection and transmission are repeated between the movable thin film and the flat substrate, and only the wavelength of an integer multiple of the distance between the flat substrate and the movable thin film passes through the light modulation element. A so-called multilayer interference effect can be obtained. This transmitted light is used as modulated light.

Further, in the optical modulation of the optical modulator according to any one of claims 1 to 2, the movable thin film is brought close to the plane substrate by applying a voltage to the plane electrode, so that the total reflection surface of the plane substrate is totally reflected. Light can be extracted from the planar substrate to the movable thin film by changing the reflection condition. In this light modulation element, when a voltage is applied to the electrode of the movable thin film and the electrode of the flat substrate, the movable thin film is displaced by the electrostatic force acting between the electrode of the movable thin film and the electrode of the flat substrate. At this time, for example, the light incident on the flat substrate is guided to the movable thin film due to a change in the total reflection condition at the total reflection interface, and the light is extracted. On the other hand, when no voltage is applied, the movable thin film elastically returns to its original position and is in a non-displaced state, and the light incident on the flat substrate is totally reflected by the total reflection surface and is not guided to the movable thin film and reflected. The light is emitted again from the flat substrate.

If the narrow portion narrower than the width of the central portion of the movable thin film is formed near both ends of the movable thin film in the longitudinal direction, the narrow portion is deformed. As a result, the driving force of the movable thin film is reduced as compared with the case of deforming the movable thin film having a uniform width, and the driving speed can be increased.

According to a third aspect of the present invention, there is provided a light modulation element array in which the light modulation elements according to the first or second aspects are arranged on the same plane.
It is characterized in that a plurality of the movable thin films are arranged close to each other in a direction orthogonal to the longitudinal direction.

In this light modulation element array, a plurality of light modulation elements are arranged side by side in the direction orthogonal to the longitudinal direction of the movable thin film on the same plane, so that the same number of pixels as the light modulation elements are arranged. With a number, one line can be optically modulated at the same time.

According to a fourth aspect of the present invention, there is provided an exposure apparatus for the light modulation element array according to the third aspect, a laser light source for irradiating the light modulation element array with a light beam, and a photosensitive material sensitive to the light beam. It is characterized by comprising a moving means for relatively moving the light emitted from the light modulation element array in the main scanning direction and the sub scanning direction orthogonal to the main scanning direction.

In this exposure apparatus, the light modulating element array according to the third aspect is used, the light modulating element array is irradiated with light from the laser light source, and the light emitted from the light modulating element is transferred to the photosensitive material by the moving means. The photosensitive material can be directly scanned and exposed by irradiating the photosensitive material while relatively moving it.

An exposure apparatus according to a fifth aspect of the present invention is a light modulation element array according to the third aspect, a laser light source for irradiating the light modulation element array with a light beam, and light emitted from the light modulation element array. With respect to the condensing lens and the light-sensitive material that is sensitive to the light beam, the light emitted from the condensing lens is moved relative to the main scanning direction and the sub-scanning direction orthogonal to the main scanning direction. And means.

In this exposure apparatus, the light modulation element array according to the third aspect is used, the light modulation element array is irradiated with light from a laser light source, and the light emitted from the light modulation element is condensed by a condenser lens. Then, by irradiating the photosensitive material with the emitted light while moving the emitted light relative to the photosensitive material by the moving means, the photosensitive material can be directly subjected to scanning exposure, and an optical system almost similar to contact exposure can be configured.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a light modulator, a light modulator array, and an exposure apparatus using the same according to the present invention will be described in detail below with reference to the drawings. Figure 1
2 is a cross-sectional view showing the structure of the light modulation element according to the present invention, FIG. 2 is a plan view of the light modulation element shown in FIG. 1, and FIG. 3 is a cross-sectional view showing the layer structure of the light transmission part shown in FIG. 4 is a cross-sectional view illustrating an operating state of the light modulation element shown in FIG.

As shown in FIG. 1, the light modulation element 100 includes
A transmissive optical modulator, which is transparent to the light to be modulated, and a space (gap) formed on the upper surface of the planar substrate 23 by a method such as formation / removal of a sacrificial layer.
The movable thin film 27 is arranged in parallel with the movable thin film 27 in parallel with each other. The movable thin film 27 has elasticity and is formed in a rectangular shape.
It is supported above via a support portion 29. Light modulator 100
As shown in FIG. 2, a plurality of movable thin films 27 are formed in a one-dimensional array shape, for example, on the same plane in the vicinity of a direction orthogonal to the longitudinal direction.

A supporting portion 29 erected on the flat substrate 23.
Is made of, for example, silicon oxide, silicon nitride, ceramic, resin, or the like. The upper end of the support portion 29 is joined to the movable thin film 27. The movable thin film 27 has a structure in which a plane electrode (movable electrode) 31 and a diaphragm 33 are sequentially laminated. The movable electrode 31 is made of a metal or a metal compound having conductivity. This metal is gold,
Silver, palladium, zinc, aluminum, copper or the like can be used, and as the metal compound, these compounds can be used. The diaphragm 33 is made of ceramic,
In addition to resins and the like, semiconductors such as polysilicon, insulating silicon oxides, silicon nitrides, various oxides, and nitrides can be used.

On the other hand, the flat substrate 23 is a glass substrate 35,
It has a structure in which a planar electrode (fixed electrode) 37 and an insulating film 39 are sequentially laminated. As the fixed electrode 37, a metal thin film such as aluminum similar to the movable electrode 31 can be used. For the insulating film 39, the same ceramic, resin, or the like as the diaphragm 33 can be used. In addition to this, for the glass substrate 35, a resin such as polyethylene terephthalate or polycarbonate can be used.

By the way, a movable thin film side non-electrode portion 41 that divides the movable electrode 31 formed on the movable thin film 27 into both ends in the longitudinal direction is provided at the central portion in the longitudinal direction of the movable thin film 27. Further, the flat substrate 23 is also provided with a substrate-side non-electrode portion 43 facing the movable thin film-side non-electrode portion 41. The movable thin film 27 side of the substrate-side non-electrode portion 43 is formed of the insulating film 39, and it is particularly preferable that this portion is formed of a material transparent to the modulated light. As shown in FIG. 2, the electrodes of the movable thin film side non-electrode part 41 and the substrate side non-electrode part 43 are removed. In the light modulation element 100, the movable thin film side non-electrode part 41 and the substrate side non-electrode part 43 serve as a light transmission part to perform light modulation. Note that the dimensions at each part in FIG. 2 are, for example, a = 150 μm, b = 20 μm, c
= About 50 μm.

Further, in the light modulation element 100 of the present embodiment, the movable reflection film 45 is formed on the movable thin film side non-electrode part 41 of the movable electrode 31, and is fixed to the substrate side non-electrode part 43 of the flat substrate 23. The reflective film 47 is formed. As shown in FIG. 3, the movable reflection film 45 and the fixed reflection film 47 are formed of a ZnO ₂ / SiO ₂ multilayer film (for example, a multilayer film of 7 layers each). The movable reflective film 45 and the fixed reflective film 47 have a function as a so-called half mirror due to the multilayer interference effect.

In the above light modulation element 100, as shown in FIG. 4, the drive voltage V _ON is applied to the movable electrode 31 of the movable thin film 27 and the fixed electrode 37 of the flat substrate 23, so that the movable thin film 27 is moved. Due to the electrostatic force acting between the movable electrode 31 and the fixed electrode 37 of the flat substrate 23, the movable thin film 2
7 is elastically deformed by the suction force to the side of the flat substrate 23,
It is displaced so as to be close to the upper surface of the planar substrate 23. On the other hand, when the attraction force due to the electrostatic force disappears, the elastic thin film 27 returns to the center with the elastic restoring force of the movable thin film 27 at a position separated by the gap 25. The light modulation element 100 allows the light in a specific wavelength range to be transmitted or reflected by coherence by the displacement or elastic return of the movable thin film 27.

Here, the movable reflection film 45 and the fixed reflection film 47 of the light modulation element 100 of this embodiment will be described in detail. The light modulation element 100 is
Light is transmitted or reflected by changing the distance between the parallel mirrors composed of the movable reflection films 45 and 47 and changing the intensity of the composite wave repeatedly reflected between the parallel mirrors. That is, optical modulation using Fabry-Perot interference is performed. In Fabry-Perot interference in which reflection and transmission are repeated between parallel mirrors, only wavelengths that are approximately integral multiples of the air gap are transmitted through the light modulation element 100.

In Fabry-Perot interference, an incident light ray is repeatedly reflected and transmitted to be divided into a large number of light rays, which are parallel to each other. The transmitted rays overlap and interfere at infinity. If the angle formed by the perpendicular of the surface and the incident light ray is θ, the optical path difference between two adjacent light rays is given by x = nt · cos θ. However, n is the refractive index between the two surfaces, and t is the distance. If the optical path difference x is an integral multiple of the wavelength λ, the transmission lines reinforce each other, and if they are an odd multiple of the half wavelength, they cancel each other out. That is, if there is no phase change upon reflection, the transmitted light becomes maximum at 2nt · cos θ = mλ (1) and the transmitted light becomes minimum at 2nt · cos θ = (2m + 1) λ / 2 (2). However, m is an integer.

Here, a case will be described in which the light modulation element 100 is used to optically modulate light emitted from, for example, an ultraviolet lamp for black light (low-pressure mercury lamp). FIG. 5 is an explanatory diagram showing the spectral characteristics of the low-pressure mercury lamp for black light, and FIG. 6 is an explanatory diagram showing the light intensity transmittance of the light modulation element.

When a phosphor for black light is applied to the inner wall of the low-pressure mercury lamp, the spectral characteristic of the emitted ultraviolet light is as shown in FIG. That is, it has a central wavelength λ ₀ near 360 nm. This ultraviolet ray is used as the backlight light.

Here, in the light modulator 100, the interval of the air gap 25 when the non-driving voltage V _OFF is applied is t _OFF.
(State of FIG. 1). Further, the interval of the gap 25 when the drive voltage V _ON is applied is set to t _ON (state of FIG. 4). Further, t _ON and t _OFF are set as follows. t _ON = 1/2 × λ ₀ = 180 nm t _OFF = 3/4 × λ ₀ = 270 nm However, m = 1 λ ₀ : The central wavelength of ultraviolet rays.

Further, the movable reflection film 45 and the fixed reflection film 47.
Sets its light intensity reflectance to R = 0.85. Void 25
Is air or a noble gas, and its refractive index is n = 1. Since the ultraviolet rays are collimated, the incident angle θ that enters the light modulation element 100 is substantially zero. The light intensity transmittance of the light modulator 100 at this time is as shown in FIG. That is,
In the light modulation element 100, when the non-driving voltage V _OFF is applied between the movable electrode 31 and the fixed electrode 37, the gap 25 has an interval of t _OFF = 270 nm, and the center wavelength λ ₀ is around 360 nm shown in FIG. It hardly transmits the ultraviolet light it has. On the other hand, when the driving voltage V _ON is applied, the gap of the gap 25 becomes t
_{When ON} = 180 nm, the center wavelength λ is around 360 nm.
Allows transmission of ultraviolet rays having ₀ .

According to the light modulation element 100, the movable thin film 27 can be displaced in this way to perform light modulation in the interference mode. Further, since there is no electrode in the light transmitting portion, light absorption by the light modulation element itself is small, and light modulation can be performed with high efficiency. Further, it is possible to obtain an optical modulator that can be driven at high speed, has high output, and has a long life. Further, high speed operation of several tens [nsec] is possible with a low drive voltage (several V to several tens of V). It should be noted that, as long as the condition of interference is satisfied, the interval t of the void 25, the refractive index n, the light intensity reflectance R of the movable reflective film 45, the fixed reflective film 47, and the like may be any combination. Further, the center wavelength of the transmission spectrum can be arbitrarily changed by continuously changing the interval t according to the voltage value.
This makes it possible to continuously control the amount of transmitted light. That is, gradation control by the applied voltage becomes possible. The light modulation element 100 is configured as a transmissive light modulation element that transmits light from the movable thin film 27 side to the flat substrate 23 side, but is not limited to this, and reflects incident light to the incident light introduction side. It may be used as a reflection type light modulation element which is returned by returning. In this case as well, the same operational effects as described above are achieved.

Next, a second embodiment of the optical modulator according to the present invention will be described. FIG. 7 shows a second optical modulator according to the present invention.
FIG. 8 is a cross-sectional view showing the configuration of the embodiment, and FIG. 8 is a cross-sectional view explaining the operating state of the light modulation element shown in FIG. In the following description, the same members as those shown in FIGS. 1 to 4 are designated by the same reference numerals, and the duplicated description will be omitted. The light modulation element 200 of the present embodiment is a light modulation element utilizing total reflection, and the movable thin film 27 is suspended on the base 55 via the support portion 29. Specifically, the base 55
The fixed electrode 37 provided on the upper side of the movable thin film 27 and divided at both ends in the longitudinal direction of the movable thin film 27, the movable electrode 31 provided on the upper layer of the movable thin film 27 and divided at both ends in the longitudinal direction of the movable thin film 27, The diffusion part 53 provided in the electrode part 41 is provided.

The light diffusing portion 53 provided on the surface of the movable thin film side non-electrode portion 41 is, for example, one in which unevenness is formed on the surface of an inorganic or organic transparent material, one in which microprisms or microlenses are formed, or inorganic. , An organic porous material, or fine particles having different refractive indexes dispersed in a transparent substrate. The support portion 29 is provided on a base 55 that is transparent to the modulated light. The base 55 has two end faces that are not parallel to each other and acts as a deflection prism that changes the direction of a light beam.

In this light modulation element 200, as shown in FIG. 8, by applying the drive voltage V _ON between the movable electrode 31 of the movable thin film 27 and the fixed electrode 37 of the base 55, the movable thin film 27 is moved. The movable thin film 27 is moved by the electrostatic force acting between the movable electrode 31 of 27 and the fixed electrode 37 of the base 55.
Is attracted to the base 55 side and elastically deformed, and is displaced so as to approach the upper surface of the base 55. On the other hand, when the attractive force due to the electrostatic force disappears, the elastic restoring force of the movable thin film 27 causes the central portion of the movable thin film 27 to float again at a position separated by the gap 25.

In this light modulation element 200, when the non-driving voltage V _OFF is applied, a gap 25 (for example, air, rare gas, etc.) exists between the movable thin film side non-electrode section 41 and the substrate side non-electrode section 43. To do. In this case, when the refractive index of the base 55 is nw, the total reflection critical angle θc at the interface with air is θc = sin ⁻¹ (nw). Therefore, when the incident angle θ on the interface is θ> θc, the incident light travels while being totally reflected inside the base 55, as shown in FIG. 7.

On the other hand, when the drive voltage V _ON is applied, the movable thin film 2
When 7 and the base 55 are contacted or brought close to each other,
As shown in FIG. 8, the incident light is propagated and transmitted to the movable thin film 27 side, further diffused by the light diffusing section 53, and emitted to the front surface side. As described above, according to the light modulation element 200, the light modulation can be performed by the displacement of the movable thin film 27 due to the application of the drive voltage V _ON . In this case, the modulated light may be either transmitted light that passes through the movable thin film 27 or total reflected light that is emitted from the base 55 when the non-driving voltage V _{OFF is} applied. .

Next, a third embodiment of the optical modulator according to the present invention will be described. FIG. 9 shows a third optical modulator according to the present invention.
It is sectional drawing which shows the structure and operation state in embodiment.
The light modulation element 300 of this embodiment is a reflection-type light modulation element, and the configuration thereof is the light modulation element 100 of the first embodiment.
Is the same as. However, when the non-driving voltage V _OFF is applied between the movable electrode 31 and the fixed electrode 37, the interval t _OFF of the gap 25 is (2m + 1) λ / (4cosθ), and the driving voltage V _ON
The interval t _ON of the air gap 25 when is applied is (2 m) λ /
It is set to (4 cosθ). Here, θ is the angle of incidence of the incident light on the light modulation element 300, and represents the angle between the normal direction of the movable thin film 27 and the incident light.

In this light modulation element 300, when the non-driving voltage V _OFF is applied between the movable electrode 31 of the movable thin film 27 and the fixed electrode 37 of the flat substrate 23, as shown in FIG. 9A. , The movable thin film side non-electrode portion 41 of the movable thin film 27
The incident light introduced into is reflected by the movable reflection film 45 and the fixed reflection film 47 toward the incident light introduction side by the optical interference effect.
On the other hand, when the drive voltage V _ON is applied, the movable thin film 27 is moved by the electrostatic force acting between the movable electrode 31 of the movable thin film 27 and the fixed electrode 37 of the flat substrate 23, as shown in FIG. 9B. Is elastically deformed by the suction force to the plane substrate 23 side, and is displaced so as to be close to the upper surface of the plane substrate 23. Thereby, the introduced incident light is transmitted through the movable reflective film 45 and the fixed reflective film 47 by the optical interference effect of the movable reflective film 45 and the fixed reflective film 47, and is not reflected to the incident light introduction side.

Therefore, on the incident light introduction side of the light modulation element 300, a reflection type light modulation is realized which becomes bright when the non-driving voltage V _OFF is applied and becomes dark when the driving voltage V _ON is applied.

Next, a fourth embodiment of the optical modulator according to the present invention will be described. FIG. 10 is a cross-sectional view showing the configuration and operating state of the optical modulator according to the fourth embodiment of the present invention. The light modulation element 400 of this embodiment is a reflection-type light modulation element, and its configuration is such that the flat substrate is the silicon substrate 1.
On the surface of the silicon substrate 13, a doped layer 16 as a fixed electrode doped with impurities is formed. This doped layer 16 is the fixed electrode 15 described above.
Similarly, the movable thin film 27 is divided and formed at both ends in the longitudinal direction. Further, in the substrate-side non-electrode portion 43, the silicon substrate rises slightly higher than the thickness of the doped layer 15. On the other hand, the movable thin film 27 includes the movable thin film side non-electrode portion 4
1 is formed by a single-layer diaphragm 33, and incident light is introduced or reflected from the movable thin film 27 side to the silicon substrate 13 side.

Here, when the non-driving voltage V _OFF is applied between the movable electrode 31 and the doped layer 16, the interval t _OFF of the gap 25 is (2m + 1) λ / (4 cos θ), and the driving voltage V _ON is applied. At this time, the interval t _ON of the air gap 25 is (2 m) λ / (4
cos θ). Note that in FIG. 10, m = 0, θ = 4
This is an example of 5 °.

The refractive index n of the movable thin film 27 preferably has a relationship of n≈√ns when the refractive index of the silicon substrate 13 is ns (ns = 3.89). A preventive function can be added.
Specifically, the diaphragm 33 of the movable thin film 27 is preferably ZrO ₂ (n = 1.97), and in that case, the film thickness of the diaphragm 33 is 53.4 nm. FIG. 11 shows the relationship between the gap between the silicon substrate 13 and the movable thin film 27 and the reflectance of the device at this time. The movable thin film 2
The relationship between 7 and the refractive index of the flat substrate is preferably set similarly in each of the above-described embodiments.

In this light modulation element 400, FIG.
As shown in, when the non-driving voltage V _OFF is applied between the movable electrode 31 of the movable thin film 27 and the doped layer 16 of the silicon substrate 13, the gap 25 becomes t _OFF , and the movable thin film 27 is exposed from the outside. The incident light introduced into the movable thin film side non-electrode portion 41 is reflected to the incident light introduction side by the optical interference effect of the movable thin film 27. At this time, the reflectance of the movable thin film 27 is as high as 90% or more as shown in FIG. On the other hand, when the drive voltage V _ON is applied, the movable thin film 2
The movable thin film 27 is elastically deformed by the attractive force to the silicon substrate 13 side by the electrostatic force acting between the movable electrode 31 of No. 7 and the doped layer 16 of the silicon substrate 13, and is displaced so as to be close to the upper surface of the silicon substrate 13. To do. As a result, the space between the voids becomes approximately 0 and t _OFF . Therefore,
The incident light introduced is transmitted through the non-electrode portion 41 on the movable thin film side, absorbed by the silicon substrate 13 side, and is not reflected by the incident light introduction side.

As a result, on the incident light introduction side of the light modulation element 400, a reflection type light modulation is realized which becomes bright when the non-driving voltage V _OFF is applied and becomes dark when the driving voltage V _ON is applied. Further, circuits such as a drive circuit can be formed on the silicon substrate 13, and various additional functions can be given to the element, and the degree of freedom in design can be improved.

Next, a modification of the light modulation element of this embodiment will be described. FIG. 12 is a cross-sectional view showing a configuration and an operating state of a light modulation element as a modified example of this embodiment. The light modulation element 500 of this modified example has a configuration in which a dielectric substrate is used as a planar substrate. Other configurations are the same as those described above, and redundant description will be omitted. In the dielectric substrate 19, the diaphragm 33 of the movable thin film 27 is covered with SiO ₂ (refractive index n = 1.
46), ZnO (refractive index ns = 2.
1) can be preferably used. In addition, the movable thin film 27
When NdF ₃ (refractive index n = 1.62) is used, for example, TiO ₂ (refractive index ns = 2.62) can be preferably used. In this way, by maintaining the relationship of n = √ns, it is possible to form an antireflection film that prevents the reflection of layers, and the light transmittance of the device can be improved. Also, the dielectric substrate 1
9 and the diaphragm 33 of the movable thin film 27 may be formed by appropriately selecting a combination of refractive indexes, and therefore, as the dielectric substrate 19, other than this, a semiconductor (for example, GaAs, Ga) may be used.
N), a dielectric material, or a metal.

According to the light modulation element 500, the movable electrode 31 and the fixed electrode 15 are similar to the operation of the light modulation element described above.
When a drive voltage V _OFF is applied between the movable thin film 27 and the movable thin film 27, the incident light introduced from the outside to the movable thin film side non-electrode portion 41 of the movable thin film 27 is reflected by the movable thin film 27 to the incident light introduction side. On the other hand, when the drive voltage V _ON is applied,
The movable thin film 27 is displaced by electrostatic force so as to approach the upper surface of the dielectric substrate 19. As a result, the incident light introduced is transmitted to the dielectric substrate 19 side and absorbed by the optical interference effect of the movable thin film 27, and is not reflected to the incident light introduction side. Therefore, on the incident light introduction side of the light modulation element 500, a reflection type light modulation is realized in which the light becomes bright when the non-driving voltage V _OFF is applied and becomes dark when the driving voltage V _ON is applied.

In the configuration of each light modulation element described above, the case where the movable thin film 27 is formed in a rectangular shape and the widths at the arbitrary positions in the longitudinal direction are equal has been described.
As shown in FIG. 13, narrow portions 59 narrower than the width of the central portion may be formed in the vicinity of both ends in the longitudinal direction of the movable thin film 27. The dimensions of each part in FIG.
For example, a = 150 μm, b = 20 μm, c = 50 μm,
It is formed with d = 10 μm and e = 100 μm. By providing such a narrow portion 59, the narrow portion 59 is particularly greatly deformed, so that the driving force of the movable thin film 27 can be reduced as compared with the case where the movable thin film 27 having a uniform width is deformed, and low voltage driving is performed. The drive speed can be increased.

According to the above light modulator, the movable thin film 2
7 is formed in a rectangular shape, the movable thin film side non-electrode portion 41 in which no electrode is formed is provided in the central portion in the longitudinal direction of the movable thin film 27, and the flat substrate 23 or the base 55 also has this movable thin film side non-electrode portion. Since the substrate-side non-electrode portion 43 that faces 41 is provided, the transparent electrode does not exist in the light transmitting portion. This makes it possible to eliminate the absorption of light by the transparent electrode and prevent the transparent electrode from being deformed or destroyed due to heat generation when the light intensity is high. In addition, by simplifying the structure of the movable thin film, it is possible to drive the light modulation element at high speed and to extend the life of the light modulation element.

Furthermore, since the absorption of light is eliminated, the intensity of transmitted light can be increased and higher output can be achieved.
Further, since the movable thin film is formed in a rectangular shape and the electrode is removed as the movable thin film side non-electrode portion 41 in the entire central portion thereof, in the case of a light modulation element array in which a plurality of light modulation elements are arranged one-dimensionally, Since no electrodes are provided between the light transmitting portions of the adjacent light modulation elements, the pixel density when used in an exposure device or a display device can be made high definition.

Next, an exposure apparatus using the light modulation element array composed of the above light modulation element 100 will be described.
FIG. 14 is a perspective view showing an outline of a main part configuration of an exposure apparatus according to the present invention, FIG. 15 is an enlarged perspective view of the exposure head shown in FIG. 14, and FIG. 16 is formed using the light modulation element 100 described above. It is an expansion perspective view of another exposure part. In this embodiment, an example will be described in which the light modulation element array configured using the light modulation element 100 is applied to an exposure device 61 for photoresist used in a liquid crystal color filter manufacturing process.

As shown in FIG. 14, the exposure apparatus 61 includes a vertical flat stage 65 for adsorbing and holding the exposure object 63 on its side surface, and a light beam (ultraviolet laser) modulated in accordance with image data 67. An exposure head 71 for scanning and exposing the exposure object 63 with (light) 69. The flat stage 65 is movably supported in the X-axis direction by a guide (not shown), and the exposure head 71 is movably supported in the Y-axis direction by a guide (not shown).

A pair of nuts 73 are fixed to the corners of the back surface of the flat stage 65, and a lead screw 77 is screwed into the female thread portion 75 of the nut 73. The lead screw 7 is attached to one end of the lead screw 77.
A drive motor 79 for rotating 7 is attached,
The drive motor 79 is connected to the motor controller 81. Then, with the rotation of the lead screw 77 by the drive motor 79, the flat stage 65 is moved stepwise in the X-axis direction.

A pair of nuts 8 is provided below the exposure head 71.
3 is fixed, and a lead screw 87 is screwed into the female thread portion 85 of the nut 83. A drive motor 89 for rotating the lead screw 87 is connected to one end of the lead screw 87 via a belt,
The drive motor 89 is connected to the motor controller 81. The exposure head 71 is reciprocally moved in the Y-axis direction as the lead screw 87 is rotated by the drive motor 89. The nut 83, the lead screw 87, and the drive motor 89 form a moving unit 90 of the exposure head 71.

In this case, the exposure target 63 is formed by forming a color resist film in which an R color pigment is dispersed in an ultraviolet curable resin on a glass substrate on which a black matrix is formed. When the exposure object 63 is irradiated with the ultraviolet laser light 69, only the portion of the color resist film irradiated with the ultraviolet laser light 69 is cured to form an R color filter portion.

The exposure head 71, as shown in FIG.
The high-power ultraviolet laser light source 91 and the laser light incident from the ultraviolet laser light source 91 are collimated in the X-axis direction and X
A lens 93 that converges in a direction orthogonal to the Y plane, a light modulation element array 95 that modulates the incident laser light for each pixel according to the image data 67, and a light modulation element array 95.
The exposure unit includes a zoom lens 97 for forming an image on the surface of the exposure object 63 by changing the magnification of the laser light modulated by.

Each member constituting this exposure unit is housed in a casing 99, and the ultraviolet laser light 69 emitted from the zoom lens 97 passes through an opening (not shown) provided in the casing 99 and the exposure target object. The surface of 63 is irradiated. The zoom lens 97 is moved along the optical axis by a drive motor (not shown) to adjust the imaging magnification. Although the zoom lens is usually composed of a combination lens, only one lens is shown for simplicity of illustration.

The ultraviolet laser light source 91, the lens 93, the light modulation element array 95, and the zoom lens 97 are fixed to the casing 99 by a fixing member (not shown), and the zoom lens 97 is moved in the optical axis direction by a guide (not shown). Supported as possible. In addition, the ultraviolet laser light source 9
1 and the light modulation element array 95 are respectively connected to a controller (not shown) that controls them via a driver (not shown).

The ultraviolet laser light source 91 uses, for example, a gallium nitride based semiconductor laser. If a gallium nitride based semiconductor laser having a broad area light emitting region is used, light in the ultraviolet region with a wavelength of about 405 nm can be obtained with high output, which is advantageous for high-speed scanning.

Examples of the photosensitive material include a photosensitive material for forming a liquid crystal color filter, a photoresist for manufacturing a printed wiring board, a photosensitive cylinder for printing, a cylinder coated with a photosensitive material for printing, and a printing plate for printing. it can. These photosensitive materials can be held on a vertical flat plate stage. By holding the photosensitive material on the vertical flat plate stage, the deflection of the photosensitive material can be minimized, so that the precision of exposure can be improved.

In the light modulation element array 95, a plurality of the light modulation elements 100 are arranged side by side on the same plane in the direction orthogonal to the longitudinal direction of the movable thin film 27. In this embodiment, the juxtaposed direction is the vertical direction (X direction) in FIG. Therefore, the direction (Y direction) orthogonal to this juxtaposed direction
When the exposure target 63 and the exposure head 71 are moved relative to each other, one line of the exposure target 63 can be exposed with the same number of pixels as the number of the light modulation elements 100 arranged in parallel. By the characteristics of the light modulation element 100,
High-speed exposure is possible and long life can be realized.
The size of each part in FIG. 15 is, for example, f = 2.
mm (1000 ch) and g = 20 μm.

Next, the operation of the exposure apparatus of this embodiment will be described. The image data 67 is input to a controller (not shown) of the light modulation element array 95 to irradiate the exposure object 63 with the ultraviolet laser light 69 to be exposed, and is temporarily stored in a frame memory in the controller. The image data 67 is data in which the densities of the pixels forming the image are represented by binary values (that is, the presence or absence of dot recording).

The laser light emitted from the ultraviolet laser light source 91 of the exposure head 71 is collimated in the X-axis direction by the lens 93, converged in the direction orthogonal to the XY plane, and incident on the light modulation element array 95. To be done. The incident laser light is simultaneously modulated by the light modulation element array 95. The modulated laser light is imaged on the surface of the exposure object 63 by the zoom lens 97.

At the start of exposure, the exposure head 71 is moved to the exposure start position (origin in the X-axis direction and the Y-axis direction).
When the motor controller 81 rotates the drive motor 89 at a constant speed, the lead screw 87 also rotates at a constant speed, and with the rotation of the lead screw 87, the exposure head 7 is rotated.
1 is moved in the Y-axis direction at a constant speed.

The image data 67 stored in the frame memory is moved along with the movement of the exposure head 71 in the Y-axis direction.
However, the light modulator 1 of the light modulator array 95 for one line
The number of pixels 00 is sequentially read in pixel units, and each of the light modulation elements 100 is ON / OFF controlled according to the read image data 67. As a result, the ultraviolet laser light 69 emitted from the exposure head 71 is turned on and off, and the exposure object 63 is exposed in the X axis direction in pixel units of substantially the same number as the number of the light modulation elements 100, and in the Y axis direction. Scanning exposure for one line is performed.

When the exposure head 71 reaches the end of the exposure object 63, the exposure head 71 returns to the origin in the Y-axis direction. Then, the motor controller 81 causes the drive motor 79
When the lead screw 77 rotates at a constant speed, the lead screw 77 also rotates at a constant speed, and as the lead screw 77 rotates,
The flat stage 65 is moved one step in the X-axis direction. The main scan and the sub scan described above are repeated to expose the exposure target 6
3 is imagewise exposed. In the above, the exposure head 7
Although the example in which 1 is returned to the origin and the exposure is performed only on the outward path has been described, the exposure may be performed on the return path.
Thereby, the exposure time can be further shortened.

According to the exposure device 61, the light modulating element array 95 is moved by the moving means in the direction orthogonal to the direction in which the light modulating elements are arranged in parallel in the light modulating element array 95. A light-sensitive material having sensitivity in a region can be directly scanned and exposed based on digital data, and even in this case, high-speed exposure is possible and a long life can be realized.

Further, since the high-power ultraviolet laser light source is used, the exposure object having sensitivity in the ultraviolet region can be directly scanned and exposed based on the digital data. As a result, compared to the exposure system of the proximity method,
(1) The cost can be reduced because a mask is unnecessary. As a result, productivity is improved, and it is also suitable for small-lot production of a wide variety of products. (2) Direct scanning exposure is performed based on digital data, so data can be appropriately corrected, and a highly accurate holding mechanism and alignment mechanism are provided. , And the temperature stabilization mechanism is not required, and the cost of the device can be reduced. (3) The ultraviolet laser light source is cheaper and more durable than the ultra-high pressure mercury lamp, and the running cost can be reduced. Yes, (4) the ultraviolet laser light source has an advantage that the driving voltage is low and the power consumption can be reduced.

Further, since the optical modulator 100 having the movable thin film side non-electrode part 41 and the substrate side non-electrode part 43 is used, the conventional optical element for modulating transmitted light (PLZT element).
Compared with the configuration using a liquid crystal light shutter (FLC) or the like, the absorption of incident light can be significantly reduced, and the durability against ultraviolet laser light can be improved. As a result,
Even when exposure is performed using a high-power ultraviolet laser as a light source, the reliability of the exposure apparatus can be significantly improved. Further, since the light modulation element array 95 is driven by an electromechanical operation utilizing electrostatic force, it is possible to obtain an operation speed up to about several tens [nsec] with a low driving voltage (several V to several tens of V). In addition to the effect that the durability of is improved, high-speed exposure is also possible.

In this embodiment, an example in which the high power laser light source is an ultraviolet laser light source composed of a GaN semiconductor laser and a multiplexing optical system has been described. You may comprise by any one of 1)-(5). (1) Gallium nitride semiconductor laser. Preferably, a gallium nitride based semiconductor laser having a broad area light emitting region. (2) A semiconductor laser-excited solid-state laser that emits a laser beam obtained by exciting a solid-state laser crystal with a semiconductor laser after wavelength conversion with an optical wavelength conversion element.
(3) A fiber laser in which a laser beam obtained by exciting a fiber with a semiconductor laser is wavelength-converted by an optical wavelength conversion element and emitted. (4) A high-power laser light source including the laser light source or lamp light source according to any one of the above (1) to (3) and a multiplexing optical system. Further, although the emission wavelength of the light source is ultraviolet in the present embodiment, any wavelength of infrared, visible, and ultraviolet may be used.

Further, in the above-mentioned embodiment, the structure in which the modulated light which has passed through the light modulation element array 95 is adjusted in focus by the zoom lens 97 and is irradiated on the exposure object 63, is explained. As shown in FIG. 16, a condenser lens 113 such as a rod lens is arranged between the light modulation element array 95 and the photosensitive drum 111, and the modulated light from the light modulation element array 95 is supplied to this condenser lens 113. Alternatively, the light may be condensed by the above method to expose the object to be exposed.

According to this structure, the modulated light from the light modulation element array 95 is condensed by the condenser lens 113 and is directly exposed on the photosensitive material, so that there is an advantage that an optical system close to contact exposure can be constituted. is there. Here, an example in which the photosensitive drum which is the outer drum is used as the moving means has been described, but the present invention is not limited to this, and another moving means such as an inner drum or a flat bed may be used.

The preferred embodiments of the light modulator, the light modulator array, and the exposure apparatus of the present invention described above are summarized as follows. (1) The movable thin films are arranged facing each other with a space on the planar substrate, and planar electrodes are provided on both the substrate and the movable thin film, and the movable thin film is generated by an electrostatic force generated by applying a voltage to each of the planar electrodes. Is a transmissive light modulation element that displaces relative to the planar substrate to change the amount of light transmitted through the movable thin film, wherein the movable thin film is formed in a rectangular shape and is supported at both longitudinal ends, and A movable thin film side non-electrode portion not having the planar electrode is formed at a central portion in the longitudinal direction of the movable thin film, and the planar substrate is a substrate side not having the planar electrode at a position facing the movable thin film side non-electrode portion. An optical modulation element having an electrode portion formed. (2) The movable thin films are arranged facing each other with a space on the planar substrate, and planar electrodes are provided on both the substrate and the movable thin film, and the movable thin film is generated by electrostatic force generated by applying a voltage to each of the planar electrodes. Is a reflection-type light modulation element that displaces with respect to the planar substrate to change the amount of light reflected by the movable thin film, wherein the movable thin film is formed in a rectangular shape and is supported at both longitudinal ends, and An optical modulation element, wherein a movable thin film side non-electrode portion having no plane electrode is formed at a central portion in the longitudinal direction of the movable thin film. (3) The light modulator according to the above (1) or (2), wherein incident light is applied to a part or the whole area of the movable thin film side non-electrode portion.

(4) The optical modulation is to generate an optical interference effect by displacing the movable thin film by applying a voltage to the planar electrode. The optical modulation element according to any one of 1). (5) The light modulation causes the movable thin film to approach the planar substrate by applying a voltage to the planar electrode, thereby changing the total reflection condition on the total reflection surface of the planar substrate,
The light modulation element according to any one of (1) to (3), wherein light is extracted from the flat substrate to the movable thin film. (6) The light according to any one of (1) to (5), characterized in that a narrow portion narrower than the width of the central portion of the movable thin film is formed near both ends in the longitudinal direction of the movable thin film. Modulation element. (7) A plurality of the light modulation elements according to any one of (1) to (6) are arranged side by side on the same plane in a direction orthogonal to the longitudinal direction of the movable thin film. An optical modulator array characterized by:

(8) The light modulation element array of (7) above,
A laser light source that irradiates the light modulation element array with a light beam, and a light-sensitive material that is sensitive to the light beam, emits light from the light modulation element array in a main scanning direction and a sub-direction that is orthogonal to the main scanning direction. An exposure apparatus comprising: a moving unit that relatively moves in the scanning direction. (9) The light modulation element array according to (7), a laser light source that irradiates the light modulation element array with a light beam, a condenser lens that condenses light emitted from the light modulation element array, and the light beam. And a moving unit that relatively moves the emitted light condensed by the condenser lens in the main scanning direction and in the sub-scanning direction orthogonal to the main scanning direction with respect to the photosensitive material that is sensitive to. Exposure equipment.

[0076]

As described in detail above, according to the optical modulator of the present invention, the movable thin film is formed in a rectangular shape, and no electrode is formed at the center of the movable thin film in the longitudinal direction. Side non-electrode part is provided, and in the case of a transmissive type, a substrate side non-electrode part is also provided on a flat substrate at a position facing the movable thin film side non-electrode part. Since the light modulation is performed in the portion, the transparent electrode does not exist in the light transmitting portion or the light reflecting portion of the movable thin film and the flat substrate, and light absorption that occurs when the transparent electrode is provided can be eliminated. As a result, it is possible to prevent deformation and destruction of the transparent electrode due to heat generation that occurs when the light intensity is high, enable high-speed driving of the light modulation element, and realize a long life of the light modulation element. Further, in the case of the reflection type, by providing the movable thin film side non-electrode portion in which no electrode is formed on the movable thin film, it is possible to eliminate light absorption. Further, according to the optical modulation element array of the present invention, since the plurality of optical modulation elements are arranged side by side in the direction orthogonal to the longitudinal direction of the movable thin film on the same plane, the number of optical modulation elements arranged in parallel is set. With the same number of pixels, it is possible to simultaneously perform optical modulation for one line. Further, according to the exposure apparatus of the present invention, since the light modulation element array, the high-power laser light source for emitting the light beam, and the moving means for relatively moving the light emitted from the light modulation element array are provided, The material can be directly scan exposed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of an optical modulator according to the present invention.

FIG. 2 is a plan view of the light modulation element shown in FIG.

FIG. 3 is a cross-sectional view showing a layer structure of a light transmitting portion of the light modulation element shown in FIG.

FIG. 4 is a sectional view illustrating an operating state of the light modulation element shown in FIG.

FIG. 5 is an explanatory diagram showing spectral characteristics of a low-pressure mercury lamp for black light.

FIG. 6 is an explanatory diagram showing a light intensity transmittance of a light modulation element.

FIG. 7 is a sectional view showing a configuration of a light modulation element according to a second embodiment of the present invention.

FIG. 8 is a cross-sectional view explaining an operating state of the light modulation element shown in FIG.

FIG. 9 is a cross-sectional view showing a configuration and an operating state of a light modulation element according to a third embodiment of the present invention.

FIG. 10 is a cross-sectional view showing a configuration and an operating state of a light modulator according to a fourth embodiment of the present invention.

FIG. 11 is a diagram showing the relationship between the gap between the silicon substrate and the movable thin film and the reflectance of the element.

FIG. 12 is a cross-sectional view showing a configuration and an operating state of a modified example of the light modulation element according to the fourth embodiment.

FIG. 13 is a plan view showing a modified example of a light modulation element in which a movable thin film is provided with a narrow portion.

FIG. 14 is a perspective view showing an outline of a main part configuration of an exposure apparatus according to the present invention.

15 is an enlarged perspective view of the light modulation element array shown in FIG.

FIG. 16 is an enlarged perspective view of another exposure unit configured using the light modulation element according to the present invention.

FIG. 17 is a cross-sectional view of a conventional light modulation element.

[Explanation of symbols]

13 ... Silicon substrate 16 ... Dope layer 15 ... Planar electrode 23 ... Planar substrate 25 ... Void (spacing) 27 ... Movable thin film 55 ... base 31 ... Movable electrode (planar electrode) 37 ... Fixed electrode (planar electrode) 41 ... Movable thin film side non-electrode part 43 ... Non-electrode part on substrate side 59 ... Narrow part 61 ... Exposure device 63 ... Object to be exposed (photosensitive material) 69 ... Ultraviolet laser light (light beam) 90 ... Transportation means 91 ... Ultraviolet laser light source (high power laser light source) 95. Light modulation element array 100, 200, 300, 400, 500 ... Optical modulator 113 ... Condensing lens

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04N 1/036 H01L 21/30 516D 5F046 1/04 B41J 3/21 V 1/113 H04N 1/04 104Z B F-term (reference) 2C162 AE28 AE40 AE47 FA06 FA09 FA10 2H041 AA13 AB40 AC06 AZ01 AZ05 AZ08 2H097 AA03 BB01 CA12 CA17 LA10 5C051 AA02 CA07 DA02 DB02 DB04 DB06 DB07 DB22 DB30 DB04 DC07 DE05 5C072 A01 BA03 HA02 A03 BA05 HA02A05 BA03HA02 CB27

Claims (5)

[Claims] 1. A planar thin film is provided with a movable thin film facing each other with a space therebetween, and a flat electrode is provided on both of the substrate and the movable thin film. A transmissive light modulation element that displaces a movable thin film with respect to the flat substrate to change the amount of light transmitted through the movable thin film, wherein the movable thin film is formed in a rectangular shape and is supported at both ends in the longitudinal direction. A movable thin film side non-electrode portion having no planar electrode is formed at a central portion in the longitudinal direction of the movable thin film, and the planar substrate does not have the planar electrode at a position facing the movable thin film side non-electrode portion. An optical modulation element having a side non-electrode portion formed. 2. The movable thin films are arranged opposite to each other with a space on the planar substrate, and planar electrodes are provided on both the substrate and the movable thin film, and the electrostatic force generated by applying a voltage to each of the planar electrodes causes the movable thin films to face each other. A reflective light modulation element that displaces a movable thin film with respect to the flat substrate to change the amount of light reflected by the movable thin film, wherein the movable thin film is formed in a rectangular shape and is supported at both longitudinal ends. A light modulating element characterized in that a movable thin film side non-electrode portion having no planar electrode is formed at a central portion in the longitudinal direction of the movable thin film. 3. A light comprising a plurality of the light modulation elements according to claim 1 or 2 arranged in parallel on a same plane in a direction orthogonal to a longitudinal direction of the movable thin film. Modulator array. 4. The light modulation element array according to claim 3, a laser light source that irradiates the light modulation element array with a light beam, and a photosensitive material that is sensitive to the light beam. An exposure apparatus comprising: a moving unit that relatively moves emitted light in a main scanning direction and a sub-scanning direction orthogonal to the main scanning direction. 5. The light modulation element array according to claim 3, a laser light source that irradiates the light modulation element array with a light beam, a condenser lens that condenses light emitted from the light modulation element array, A moving means for moving the emitted light condensed by the condenser lens in the main scanning direction and in the sub-scanning direction orthogonal to the main scanning direction with respect to the photosensitive material sensitive to the light beam. Characteristic exposure equipment.