KR101912718B1 - Optical image shutter and method of fabricating the same - Google Patents

Abstract

An optical image shutter and its manufacturing method are provided. The optical image shutter includes a first thin film layer having a refractive index varied according to an electric field, first and second electrodes spaced apart with an all thin film layer sandwiched therebetween, and a first thin film layer disposed between the first thin film layer and the thin film layer, And an electrification preventing layer disposed in at least one region to prevent current flow into the electrophoretic thin film layer.

Description

Technical Field [0001] The present invention relates to an optical image shutter and a manufacturing method thereof,

Embodiments of the present invention relate to optical image shutters and methods of making same.

An optical shutter has a function of transmitting or blocking an optical image containing information according to a control signal. The optical shutter is an optical module widely used in an image pickup apparatus such as a camera or the like.

Recently, a technique for measuring distance information of a subject to acquire a three-dimensional stereoscopic image has been studied. Light of a specific wavelength (for example, near-infrared light of 850 nm) is projected onto a subject by using an LED (Light Emitting Diode) or a LD (Laser Diode) for the measurement of distance, and after a light image reflected from the subject is shuttered, Acquire the image through the device. Then, distance information is obtained through a series of processing on the acquired image. In this process, a fast shutter opening and closing time of several ns is required to accurately identify the travel time of light along the distance.

An optical shutter of the semiconductor substrate 10 is proposed as an optical shutter capable of providing such a fast shutter opening / closing time. Since a semiconductor-based optical shutter forms an electro-optical material as a thin film, it can function as an optical shutter even at a low voltage, and a semiconductor-based optical shutter technology is being studied.

The present disclosure provides an optical image shutter capable of reducing leakage current and a method of manufacturing the same.

According to one aspect of the present invention, there is provided an optical image shutter comprising: an all optical thin film layer whose refractive index is changed according to an electric field; First and second electrodes spaced apart by the electro-optic thin film layer therebetween; And an electrification preventing layer disposed in at least one of the first electrode and the all-light thin-film layer and between the second electrode and the all-light thin-film layer to prevent current from flowing into the all-light thin-film layer.

In addition, the electro-optic thin film layer is _{KTa 1 - x Nb x O 3} (0≤x≤1) (KTN), LiNbO 3 (LN), Pb (ZrO 1-x Ti x) O 3 (0≤x≤1) ( PZT) and 4-dimethylamino-N-methyl-4 stilbazolium (DAST).

In addition, the electrification preventing layer may be formed of an insulating material.

The lattice constant of the insulating material may be similar to the lattice constant of the electro-optic thin film layer.

The electrification preventing layer may be composed of at least one of ZrO2, TiO2, MgO, SrTiO3, Al2O3, HfO2, NbO, SiO2 and Si3N4.

A buffer layer disposed under the first electrode; A substrate disposed below the buffer layer; And a reflective layer disposed on the second electrode.

Further, the substrate may be a crystalline substrate.

The substrate may be formed of at least one of Si, GaAs and Sapphire, and the first electrode may be formed of a material containing at least one of Pt, Cu, Ag, Ir, Ru, Al, and Au.

A first reflective layer disposed under the first electrode; A substrate disposed below the first reflective layer; And a second reflective layer disposed on the second electrode.

The substrate may be a transparent amorphous substrate, and the first electrode may be formed of a transparent conductive oxide or a transparent oxide semiconductor.

The first electrode may be formed of SrTiO ₃ or ZnO based material.

The reflectance of the second reflective layer may be the same as the reflectivity of the first reflective layer.

According to another aspect of the present invention, there is provided a method of manufacturing an optical image shutter, comprising: forming a first electrode on a first reflective layer; Forming an all-optical thin film layer having a refractive index on the first electrode according to an electric field; Forming a second electrode on the electro-optical thin film layer, and forming a reflective layer on the second electrode, wherein at least one of a pre-electrification step and a post-formation step of the electro- And forming an electrification preventing layer for preventing the electrification preventing layer.

According to another aspect of the present invention, there is provided a method of manufacturing an optical image shutter, comprising: forming a sacrificial layer on a crystalline substrate; Forming a first reflective layer on the sacrificial layer; Forming a first electrode on the first reflective layer; Forming an electro-optic thin film layer having a refractive index that changes according to an electric field on the first electrode; Forming a second electrode on the electro-optic thin film layer; Forming a second reflective layer on the second electrode; Bonding the second reflective layer on a transparent substrate by a flip-chip bonding method; And removing the sacrificial layer to peel off the crystalline substrate on the first reflective layer, wherein at least one of the pre-forming step and the post-forming step of the pre-light thin film layer prevents current flow into the electro-optical thin film layer And forming an electrification preventing layer on the surface of the substrate.

The optical image shutter according to an embodiment of the present disclosure can achieve a cost reduction and a yield improvement by using a low-cost transparent substrate such as a glass substrate or the like to form a crystalline all-optical thin film layer at a low temperature.

Further, since the all-optical crystal can be formed in the form of a thin film on the glass substrate, the optical image shutter can consequently have a small thickness.

Since the electrification preventing layer for preventing the current from flowing between the electro-optic thin film layer and the electrodes is formed, the leakage current can be reduced.

In addition, since the electrification preventing layer similar to the lattice constant of the electroluminescence thin film layer is used, the electrification thin film layer and the electrification preventing layer can be prevented from cracking.

Furthermore, the disclosed optical image shutter can be used as a shutter for a camera and a shutter for a flat panel display because the optical image shutter can be made large-sized.

1 to 3 are sectional views showing the structure of a transmission type optical image shutter according to an embodiment of the present invention.
4A to 4D are views showing a method of manufacturing a transmissive optical image shutter according to an embodiment of the present invention.
5 to 7 are sectional views showing the structure of a reflective optical image shutter according to an embodiment of the present invention.

Hereinafter, an optical image shutter and a method of manufacturing the same according to an embodiment of the present invention will be described with reference to the accompanying drawings. The widths and thicknesses of the layers or regions illustrated in the accompanying drawings may be exaggerated somewhat for clarity of the description. Like reference numerals designate like elements throughout the specification.

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

1 to 3 are cross-sectional views illustrating the structure of a transmissive optical image shutter 100, 101, 102 according to an embodiment of the present invention. 1 to 3, a transmissive optical image shutter 100, 101, 102 includes a substrate 10, first and second reflective layers 11, 16 disposed on the substrate 10 for reflecting light of a specific wavelength band, The first and second reflective layers 11 and 16 are disposed between the first and second reflective layers 11 and 16 and centered on the all-light thin film layer 14 and the all-light thin film layer 14 in which the refractive index is changed according to the electric field. First and second electrodes 12 and 15 spaced apart from each other to apply an electric field to the electro-optic thin film layer 14 and between the first electrode 12 and the electro-optic thin film layer 14 and between the second electrode 15, And an electrification preventing layer (13, 17) disposed in at least one region between the electroluminescence thin film layer (14) and the electroluminescence thin film layer (14) to prevent current from flowing into the electroluminescence thin film layer (14).

The substrate 10 may be made of a transparent amorphous material, for example, glass, so that light can be transmitted.

The first and second reflective layers 11 and 16 may be formed to have high reflectivity with respect to light of a specific wavelength band by alternately laminating two or more kinds of transparent dielectric thin films having different refractive indices. In addition, instead of the dielectric thin film, a layer having both light transmission and reflection characteristics such as a thin metal can be used as the first and second reflective layers 11 and 16. The first reflective layer 11 and the second reflective layer 16 may be formed of the same material and have the same structure.

For example, the reflectance of the first and second reflective layers 11 and 16 may be the same and may be 97% or more, respectively. Then, the incident light is resonated between the first reflective layer 11 and the second reflective layer 16 with the electro-optic thin film layer 14 as a center, and only light having a narrow wavelength band corresponding to the resonant mode can be transmitted. Therefore, the structure including the first reflective layer 11, the electro-optic thin film layer 14, and the second reflective layer 16 serves as a Fabry-Perot filter having controllable short-wavelength transmittance characteristics. The wavelength band of the transmitted light can be controlled according to the refractive index and the thickness of the electro-optic thin film layer 14. The light transmitted through the transmissive optical image shutters 100, 101, and 102 may be photographed, for example, in an imaging device (not shown) using a CCD or CMOS image sensor.

The electro-optic thin film layer 14 may be formed of a material having an electro-optical effect whose refractive index varies depending on the magnitude of the applied electric field. Of a material of such electro-optic thin film layer 14 is, for _{example, KTa 1 - x Nb x O} 3 (0≤x≤1) (KTN), LiNbO 3 (LN), Pb (ZrO 1 -x Ti x) O ₃ (0? X? 1) (PZT) and DAST (4-dimethylamino-N-methyl-4 stilbazolium). It is important to control the crystallinity and the directionality of the electro-optic thin film layer 14 in order to improve the electro-optic effect of the electro-optic thin-film layer 14. For example, in the case of KTN, the electro-optic thin film layer 14 may have a structure of a perovskite material with a lattice constant of a = 3.9A for the electrooptic effect.

The first and second electrodes 12 and 15 may be formed of the same material or may be formed of another material for applying an electric field to the electro-optic thin film layer 14. E.g,

For example, the first electrode 12 may be a transparent metal oxide made of a material similar to the lattice constant of the electro-optic thin film layer 14. Since the optoelectronic thin film layer 14 such as KTN can grow a crystal thin film only on the crystallized substrate 10, it is difficult to use an amorphous substrate such as glass capable of mass production at a low cost as a substrate. In addition, even if a crystallized substrate such as Si, GaAs, Al ₂ O ₃ , MgO, SrTiO ₃ or the like is used, the optoelectronic thin film layer 14 can be formed at a high temperature process of about 700 ° C. However, such a high-temperature process may cause a characteristic change such as a refractive index change of the first reflective layer 11 and the second reflective layer 16, which are dielectric thin films.

Thus, before forming the electro-optical thin-film layer 14, the first electrode 12 is formed of a crystalline material of transparent conductive oxide (TCO) that can be crystallized at a low temperature of 300 ° C or less irrespective of the lattice constant of the lower layer . The first electrode 12 can be adjusted to have a lattice constant similar to the lattice constant of the electroluminescent thin film layer 14 in order to facilitate the crystallization of the electroluminescent thin film layer 14. [

For example, the lattice constant of the first electrode 12 can be adjusted so that the lattice mismatch with the lattice constant of the electro-optic thin film layer 14 is within 20% or within 10%. The material usable as the first electrode 12 may be SrTiO ₃ . SrTiO ₃ has the same structure of perovskite as KTN, and the lattice constant is also similar to KTN.

On the other hand, the ZnO-based material, which is a transparent oxide semiconductor, has a lattice constant a = 3.3 Å, which is similar to the lattice constant of KTN. ZnO can also be easily crystallized at a low temperature of 300 DEG C or less regardless of the crystallinity of the substrate 10. [ In addition, ZnO can easily adjust lattice constant by doping and electric conductivity can be easily improved by doping. For example, ZnO can be doped with Al or Ga to control the lattice constant and improve electrical conductivity. At this time, the doping concentration of Al or Ga may be about 1 mol%? Al or Ga? 5 mol%. Thus, a ZnO-based material can also be used to form the first electrode 12. [

In addition, a three-component or four-component ZnO-based compound having three or four compositions such as Al-In-Zn-O, In-Ga-Zn-O, Sn-Ga-Zn- A material can be used as the first electrode 12. In this case, it is possible to adjust the lattice constant and the electric conductivity of the first electrode 12 to a desired value by changing the composition of Al, In, Ga, and Sn. Further, when the first electrode 12 is formed of a ZnO / Ag / ZnO structure in which Ag, which is a metal having excellent electrical conductivity, is interposed between the ZnO-based materials in a thin film form, The conductivity can be further improved. When the first electrode 12 is formed in this manner and then the optoelectronic thin film layer 14 is formed, the manufacturing process can be performed at a relatively low temperature (for example, about 300 DEG C or less) Chengdu can also be improved.

A second electrode 15 is a common transparent metal oxide, for example, ITO (Indium Tin Oxide), AZO (Aluminium Zinc Oxide), IZO (Indium Zinc Oxide), SnO ₂ (Tin oxide) or In ₂ O ₃ Or the like. Of course, the second electrode 15 may be formed of the same material as that of the first electrode 12.

The electrification preventing layers (13, 17) prevent electrical conduction between at least one of the first and second electrodes (12, 15) and the electrophoretic thin film layer (14). The optical image shutter should correspond to the size of the imaging surface of the CCD or CMOS sensor. To this end, the aperture of the optical image shutter must have a size similar to the size of the active area of the CCD or CMOS sensor, e.g., a large aperture of about 1 cm diagonal. When the electro-optic thin film layer 14 having such a large aperture is deposited on the first electrode 12, a defect may exist on the electro-optic thin film layer 14. This drawback can cause electrical conduction between the first electrode 12 located below the electro-optic thin film layer 14 or the second electrode 15 positioned above the electro-optic thin film layer 14. And, the electrical energization described above may cause a short to reach a breakdown. Therefore, it is necessary to insert a current-carrying layer for preventing electric conduction between the electro-optic thin film layer 14 and the electrode.

The electrification preventing layers 13 and 17 may be formed of an insulating material containing at least one of ZrO ₂ , TiO ₂ , MgO, CeO ₂ , Al ₂ O ₃ , HfO ₂ , NbO, SiO ₂ and Si ₃ N ₄ . The insulating materials of the electrification preventing layers 13 and 17 may be different depending on the material properties of the electroluminescent thin film layer 14. For example, the electrification preventing layers 13 and 17 may use an insulating material similar to the lattice constant of the electroluminescent thin film layer 14. Thus, when KTN is used as the electrochromic thin film layer 14, MgO having a lattice constant similar to that of KTN can be used as the electrification preventing layers 13 and 17. MgO having a lattice constant a = 4.21 Å can be used as the electrification preventing layers 13 and 17 when the lattice constant of KTN is a = 3.3 Å.

The electrification preventing layers 13 and 17 may be disposed between the first electrode 12 and the electroluminescence thin film layer 14 as shown in FIG. 1, and the electroluminescence thin film layer 14 and the second electrode (15). ≪ / RTI > In addition, it may be disposed between the first electrode 12 and the all-light thin-film layer 14 and between the all-light thin-film layer 14 and the second electrode 15 as shown in FIG.

On the other hand, when the electro-optic thin film layer 14 is made of KTN, it is more effective to prevent the electrification by using MgO rather than SiO ₂ as the electrification preventing layers 13 and 17. This is because the crystal crystals of MgO and KTN are similar to each other, and a dense crystal film can be deposited on the same substrate 10. Table 1 below is a table showing the physical characteristics of KTN available as SiO ₂ , MgO and electro-optic thin film layer 14, which can be used as the electrification preventing layers 13 and 17.

Characteristics SiO ₂ MgO KTN

)Dielectric permittivity (

) 3.9 9.6-9.8 Energy gap (eV) 9 7.8 Thermal expansion coefficients (10 ^-6 K ^-1 ) 0.5 11.15 5.6

As shown in Table 1, SiO ₂ and MgO have an energy band gap of 7 eV or more, and thus have excellent insulating properties. In addition, MgO has a dielectric constant twice as high as that of SiO ₂ , so that the applied electric field of KTN can be doubled. The thermal expansion coefficient of MgO is closer to KTN than that of SiO ₂ , and the stress due to the temperature change during the process is relatively smaller than that of SiO ₂ . Thus, when MgO is used for the antistatic layers 13 and 17, cracking of the MgO or KTN layer can be prevented. In addition, if diffusion of MgO occurs in KTN, diffusion can result in a doping effect that contributes to a reduction in dielectric loss. Thus, the leakage current is reduced.

는 하기 수학식 1과 같이 전광 박막층(14)의 굴절률과 두께에 따라 결정된다.The operation principle of the optical image shutter is as follows. Center wavelength of optical image shutter

Is determined according to the refractive index and thickness of the electro-optic thin film layer 14 as shown in the following Equation (1).

Here, m is a positive integer, and n and d are the refractive index and thickness of the electro-optic thin film layer 14, respectively.

On the other hand, the electrooptic effect means that the refractive index of the electro-optic thin film layer 14 is changed when an electric field is applied to the electrooptic thin film layer 14, such as a Pockel effect and a Kerr effect. Considering the Kerr effect, the refractive index change value n 'can be expressed as a function of the voltage difference V applied to the first and second electrodes 12 and 15 as shown in Equation (2).

는 전광 박막층(14)의 커계수(Kerr efficient)로서, KTN인 경우 커계수는

이다. 즉 전광 박막층(14)의 아래 및 위에 배치된 제1 및 제2 전극(12, 15)에 전압을 인가하면 전광 효과에 의해 전광 박막층(14)의 굴절률이 변화하고 그에 따라서 수학식 1에서 정의된 광이미지　셔터의 중심파장도 하기 수학식 3과 같이 변하게 된다.here

(Kerr efficient) of the electro-optic thin film layer 14, and the K coefficient for KTN is

to be. That is, when a voltage is applied to the first and second electrodes 12 and 15 disposed below and above the electro-optic thin film layer 14, the refractive index of the electro-optic thin film layer 14 changes due to the electrooptic effect, The center wavelength of the optical image shutter also changes as shown in the following equation (3).

Accordingly, the light transmission characteristics of the optical image shutter can be changed by adjusting the voltage difference applied to the first and second electrodes 12 and 15. [ For example, if a light having a center wavelength of about 850 nm can pass through the optical image shutter before the electric field is applied to the electric thin film layer 14, if a voltage of 20 V is applied to the upper and lower portions of the electric thin film layer 14, An electric field is generated in the thin film layer 14 and the refractive index changes. Then, light having a center wavelength of about 870 nm may pass through the optical image shutter while changing the transmission characteristics of the optical image shutter. Here, the transmitted wavelengths of 850 nm and 870 nm are merely illustrative, and the transmission wavelength can be controlled according to the refractive index and thickness of the electro-optic thin film layer 14 and the design of the first and second reflective layers. The light transmission characteristics before and after the application of the electric field to the all-light thin film layer 14 are changed, and the optical image shutter can serve as a shutter for electrically controlling light having a specific wavelength band.

Deposition of each layer included in the transmissive optical image shutters 100, 101, and 102 may be performed by chemical vapor deposition, sputtering, pulsed laser deposition (PLD), or the like. However, when the glass substrate 10 is used for the transmissive optical image shutters 100, 101, and 102, the glass substrate 10 is an amorphous substrate, while the first reflective layer is a crystalline material, ). ≪ / RTI > In this case, the first reflective layer, the first electrode 12, the electrification preventing layers 13 and 17, the electro-optic thin film layer 14, the second electrode 15, and the second reflective layer 13 are formed using the substrate 10 having good crystallinity. A part of the formed translucent optical imaging shutter may be bonded to a transparent substrate 10 such as glass by a flip-chip bonding technique. Figures 4A-4D illustrate a method of manufacturing a light image shutter in this manner.

4A, a sacrificial layer 21, a second reflective layer 16, and a second electrode 15 are sequentially formed on a crystalline substrate 20 such as Si or GaAs. Since the crystalline substrate 20 is to be removed later, it is not necessarily transparent, but may be made of a material having excellent crystallinity. The second reflective layer 16 and the second electrode 15 are applied as described above. The electroluminescent thin film layer 14, the electrification preventing layer 13, the first electrode 12 and the first reflective layer 11 can be continuously formed on the second electrode 15. Here, the electrooptic thin film layer 14 may be formed to a thickness of, for example, 5 탆 or less.

Next, referring to FIG. 4B, the first reflective layer 11 is bonded onto a transparent substrate 10 such as glass using, for example, a flip-chip bonding technique. When the sacrifice layer 21 is removed as shown in FIG. 4C, the crystalline substrate 20 is separated from the first reflective layer 11. Then, finally, the transmission type optical image shutter 100 having the structure as shown in FIG. 4D can be formed.

In the case of the transmissive optical image shutter 100 shown in FIG. 4D, the electrification preventing layer 13 is formed between the electrophoretic thin film layer 14 and the first electrode 12, but the electrification thin film layer 14 and the second electrode 15 are formed, The electrification preventing layer 17 may be formed. In addition, the electrification preventing layers 13 and 17 may be formed between the electroluminescence thin film layer 14 and the first electrode 12, and between the electroluminescence thin film layer 14 and the second electrode 15.

Although the transmission type optical image shutters 100, 101, and 102 have been described so far, it is also possible to construct a reflection type optical image shutter with the same structure as described above.

5 is a cross-sectional view showing the structure of the reflective optical image shutters 300, 301, and 302 according to an embodiment of the present invention. 5, the reflective optical image shutter 300 includes a substrate 30, a buffer layer 31 disposed on the substrate 30, a first electrode 32 disposed on the buffer layer 31, The electrification preventing layers 33 and 37 disposed on the electrification preventing layers 33 and 37, the electroluminescence thin film layer 34 disposed on the electrification preventing layers 33 and 37, the second electrode 35 and the second electrode 35 disposed on the electroluminescence thin film layer 34, And a reflective layer 36 disposed thereon.

Since the reflective optical image shutter 300 shown in FIG. 5 is of a reflection type, it is not necessary to use a transparent substrate. For example, the reflective optical image shutter 300 may use a crystalline substrate 30 such as Si or GaAs.

The buffer layer 31 is a layer for crystallizing the first electrode 32 on the substrate 31 and has a thermal expansion coefficient As shown in FIG. For example, the buffer layer 31 may be formed of at least one of oxides such as SiO ₂ , P ₂ O ₅ , TiO ₂ , Li ₂ O, and BaO.

In addition, in the case of the reflective optical image shutter 200, the first electrode 31 may be an opaque material in order to operate in a reflective mode. The first electrode 32 may be a metal material including at least one of Pt, Cu, Ag, Ir, Ru, Al, and Au having high electrical conductivity and reflectivity. The reflectance of the first electrode 32 may be, for example, about 90% or more.

The electrification preventing layer 33 may be formed of an insulating material containing at least one of ZrO ₂ , TiO ₂ , MgO, CeO ₂ , Al ₂ O ₃ , HfO ₂ , NbO, SiO ₂ and Si ₃ N ₄ . The insulating material of the electrification preventing layer 33 may be different depending on the material properties of the electroluminescent thin film layer 34. [ For example, the electrification preventing layer 33 may use an insulating material similar to the lattice constant of the electroluminescent thin film layer 34. [ Thus, when KTN is used as the all-optical thin film layer 34, MgO having a lattice constant similar to that of KTN can be used as the electrification preventing layer 33. MgO having a lattice constant a = 4.21 ANGSTROM can be used as the electrification preventing layer 33 when the lattice constant of KTN is a = 3.3 ANGSTROM.

The optoelectronic thin film layer 34 may be formed of a material having an electro-optical effect whose refractive index varies depending on the magnitude of an applied electric field. Of a material of such electro-optic thin film layer 34 is, for _{example, KTa 1 - x Nb x O} 3 (0≤x≤1) (KTN), LiNbO 3 (LN), Pb (ZrO 1 -x Ti x) O ₃ (0? X? 1) (PZT) and DAST (4-dimethylamino-N-methyl-4 stilbazolium). It is important to control the crystallinity and the directionality of the electro-optic thin film layer 34 in order to improve the electro-optic effect of the electro-optical thin-film layer 34. For example, in the case of KTN, the optoelectronic thin film layer 34 may have a structure of a perovskite material having a lattice constant of a = 3.9A for the electrooptic effect.

The second electrode 35 is a common transparent metal oxide, for example, ITO (Indium Tin Oxide), AZO (Aluminium Zinc Oxide), IZO (Indium Zinc Oxide), SnO ₂ (Tin oxide) or In ₂ O _3, etc. .

The reflective layer 36 may have a low reflectivity, for example, about 50%. Accordingly, the incident light is subjected to Fabry-Perot resonance between the first electrode 31 and the reflective layer 36, and ultimately, is output to the reflective layer 36 having a relatively low reflectance. The reflective layer 36 may be formed to have reflectivity with respect to light of a specific wavelength band by alternately laminating two or more kinds of transparent dielectric thin films having different refractive indexes.

On the other hand, the electrification preventing layers 33 and 37 may be disposed between the photoelectric layer 34 and the second electrode 35, as shown in Figs. 6 and 7.

The reflective optical image shutters 300, 301, and 302 shown in FIGS. 5 through 7 may deposit the buffer layer 31 on the substrate 30 by a flip-chip bonding technique. The electrification preventing layer 33 and / or 37 and the electro-optic thin film layer 34 may be deposited by a PLD deposition process. Accordingly, the reflective optical image shutters 300, 301, and 302 may be sequentially stacked on the substrate 30 in the order of the buffer layer 31, the first electrode 32, and the like.

As described above, according to the present invention, it is possible to form an all-optical thin film layer of a crystalline state at a low temperature by using an inexpensive transparent substrate such as a glass substrate or the like. Therefore, in manufacturing the optical image shutter, the cost reduction and the yield improvement effect can be obtained. Further, since the all-optical crystal can be formed in the form of a thin film on the glass substrate, the resulting optical image shutter can have a small thickness. For example, the total thickness of the manufactured optical image shutter may be 100 탆 to 1 mm, and 100 탆 or less excluding the substrate.

In addition, since the electrification preventing layer for preventing the flow of current between the electro-optic thin film layer and the electrodes is formed, not only the leakage current can be reduced but also the electrification preventing layer similar to the lattice constant of the electro- Cracks can be prevented.

Since the optical image shutter using such a crystalline all-optical thin film layer can have a very fast shutter opening / closing speed of several ns and can be made large-sized, it can be used as a shutter in various optical devices such as a camera, a flat panel display, an optical modulator, a 3D camera, and a LADAR Can be used.

Up to now, illustrative embodiments of optical image shutters and methods of making the same have been described and shown in the accompanying drawings to facilitate understanding of the present invention. It should be understood, however, that such embodiments are merely illustrative of the present invention and not limiting thereof. And it is to be understood that the invention is not limited to the details shown and described. Since various other modifications may occur to those of ordinary skill in the art.

10, 30: substrate 11: first reflective layer
12, 32: first electrode 13, 17, 33, 37:
14, 34: all-optical thin film layer 15, 35: second electrode
16: second reflective layer 31: buffer layer
36: Reflective layer

Claims (14)

The refractive index varies with the electric field, the electro-optic thin film layer comprising a _{KTa 1-x Nb x O 3} (0≤x≤1) (KTN);
First and second electrodes spaced apart by the electro-optic thin film layer therebetween; And
And an electrification preventing layer disposed in at least one region between the first electrode and the all-light thin-film layer and between the second electrode and the all-light thin-film layer to prevent current from flowing into the all-light thin- Image Shutter. delete The method according to claim 1,
Wherein the electrification preventing layer is formed of an insulating material. The method of claim 3,
Wherein the lattice constant of the insulating material is similar to the lattice constant of the electro-optic thin film layer. delete The method according to claim 1,
A buffer layer disposed under the first electrode;
A substrate disposed below the buffer layer; And
And a reflective layer disposed on top of the second electrode. The method according to claim 6,
Wherein the substrate is a crystalline substrate. 8. The method of claim 7,
Wherein the substrate is formed of at least one of Si, GaAs, and Sapphire, and the first electrode is formed of at least one of Pt, Cu, Ag, Ir, Ru, Al, and Au. The method according to claim 1,
A first reflective layer disposed below the first electrode;
A substrate disposed below the first reflective layer; And
And a second reflective layer disposed on top of the second electrode. 10. The method of claim 9,
Wherein the substrate is a transparent amorphous substrate, and the first electrode is formed of a transparent conductive oxide or a transparent oxide semiconductor. 11. The method of claim 10,
Wherein the first electrode is formed of SrTiO ₃ or ZnO-based material. 10. The method of claim 9,
And the reflectance of the second reflective layer is equal to the reflectivity of the first reflective layer. Forming a first electrode on the first reflective layer;
Step of the refractive index varies depending on the electric field on the first electrode, forming an electro-optic thin film layer comprising a _{KTa 1-x Nb x O 3} (0≤x≤1) (KTN);
Forming a second electrode on the electro-optic thin film layer;
And forming a reflective layer on the second electrode,
And forming an electrification preventing layer made of MgO in at least one of a pre-forming step and a post-forming step of the electro-optic thin film layer to prevent current from flowing into the electro-optical thin film layer. Forming a sacrificial layer on the crystalline substrate;
Forming a first reflective layer on the sacrificial layer;
Forming a first electrode on the first reflective layer;
Step of the refractive index varies depending on the electric field on the first electrode, forming an electro-optic thin film layer comprising a _{KTa 1-x Nb x O 3} (0≤x≤1) (KTN);
Forming a second electrode on the electro-optic thin film layer;
Forming a second reflective layer on the second electrode;
Bonding the second reflective layer on a transparent substrate by a flip-chip bonding method; And
Removing the sacrificial layer to remove the crystalline substrate on the first reflective layer,
And forming an electrification preventing layer made of MgO in at least one of the pre-forming step and the post-forming step of the electro-optic thin film layer to prevent current from flowing into the electro-optical thin film layer.

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