KR20050104761A - Embedded diffractive optical modulator - Google Patents

Abstract

The present invention relates to a diffraction light modulator of the present invention, and more particularly, to an embedded diffraction light modulator in which a mirror layer is formed in a double embedded form so that an upper mirror layer and a lower mirror layer can form pixels.

In addition, the present invention is a substrate having an insulating layer formed on the surface; And a central micropart positioned away from the substrate, both ends of which are attached to the substrate, and having a double micro mirror layer having a predetermined step so as to diffract the incident light. And an element having a pair of piezoelectric layers, wherein the element is driven by shrinkage expansion of the piezoelectric layer.

Description

Embedded Diffractive Optical Modulator

The present invention relates to a diffraction light modulator of the present invention, and more particularly, to an embedded diffraction light modulator in which a mirror layer is formed in a double embedded form so that an upper mirror layer and a lower mirror layer can form pixels.

In general, optical signal processing has advantages of high speed, parallel processing capability, and large-capacity information processing, unlike conventional digital information processing, which cannot process a large amount of data and real-time processing, and design a binary phase filter using spatial light modulation theory. Research on fabrication, optical logic gates, optical amplifiers, image processing techniques, optical devices, optical modulators, etc.

The dual spatial optical modulator is used in the fields of optical memory, optical display, printer, optical interconnection, hologram, and the like, and research on the development of a display device using the same is underway.

Such a spatial light modulator is, for example, a reflective deformable grating light modulator 10 as shown in FIG. 1. Such a modulator 10 is disclosed in US Pat. No. 5,311,360 to Bloom et al.

The modulator 10 includes a plurality of regularly spaced deformable reflective ribbons 18 having reflective surface portions and suspended above the substrate 16. An insulating layer 11 is deposited on the silicon substrate 16. Next, deposition of the sacrificial silicon dioxide film 12 and the low stress silicon nitride film 14 is followed. The nitride film 14 is patterned from the ribbon 18 and a portion of the silicon dioxide layer 12 is etched so that the ribbon 18 is retained on the oxide spacer layer 12 by the nitride frame 20. In order to modulate light having a single wavelength λ _0, the modulator is designed thick with a thickness of the oxide spacers 12 of the ribbon 18 so that the λ _0/4.

The lattice amplitude of this modulator 10, defined by the vertical distance d between the reflective surface 22 on the ribbon 18 and the reflective surface of the substrate 16, is the ribbon 18 (the ribbon 16 serving as the first electrode). Is controlled by applying a voltage between the reflective surface 22 of the substrate 16 and the substrate 16 (the conductive film 24 under the substrate 16 serving as the second electrode). In the undeformed condition, that is, while no voltage is not applied, the grating amplitude is λ ₀ / equal to 2, the car full path between reflected from the ribbons and the substrate the light like a λ _0, the reinforcing phase such reflected light Let's do it. Thus, in the undeformed state, the modulator 10 reflects light as a planar mirror. The undeformed state is indicated as 20 in FIG. 2 showing incident light and reflected light.

When a proper voltage is applied between the ribbon 18 and the substrate 16, electrostatic forces deform the ribbon 18 in the down position toward the surface of the substrate 16. In the down position, the grating amplitude is changed like the λ _0/4. The total path difference is half of the wavelength, and the light reflected from the modified ribbon 18 and the light reflected from the substrate 16 have a destructive interference. As a result of this interference, the modulator diffracts incident light 26. The modified state is represented by 28 and 30 in FIG. 3, showing the light diffracted in the +/- diffraction modes (D + 1, D-1).

However, BLUM's optical modulator uses an electrostatic method to control the position of the micromirror, in which case the operating voltage is relatively high (usually around 30V) and the relationship between applied voltage and displacement is not linear. There is a disadvantage that the reliability is not high in controlling the light.

In order to solve this problem, Korean Patent Application No. P2003-077389 discloses a "thin film piezoelectric optical modulator and its manufacturing method."

4 is a cross-sectional view of a recessed thin film piezoelectric optical modulator according to the related art.

Referring to the drawings, the recessed thin film piezoelectric optical modulator according to the related art includes a silicon substrate 401 and an element 410.

Here, the element 410 has a constant width and a plurality of constant alignment to form a recessed thin film piezoelectric optical modulator. In addition, the elements 410 have different widths and are alternately arranged to form a recessed thin film piezoelectric optical modulator. In addition, the elements 410 may be spaced apart from each other at a predetermined interval (almost the same distance as the width of the element 410), in which case the micromirror layer formed on all of the upper surface of the silicon substrate 401 is incident Reflects and diffracts light.

The silicon substrate 401 has a depression to provide an air space to the element 410, an insulating layer 402 is deposited on the upper surface, and ends of the element 410 are attached to both sides of the depression. .

The element 410 has a rod shape, and the bottom surfaces of both ends are attached to both side regions outside the recessed portion of the silicon substrate 401 so that the center portion is spaced apart from the recessed portion of the silicon substrate 401. The portion located in the depression of the 401 includes a lower support 411 movable up and down.

In addition, the element 410 is stacked on the left end of the lower support 411, and is laminated on the lower electrode layer 412 and the lower electrode layer 412 for providing a piezoelectric voltage. A piezoelectric material layer 413 that expands to generate a vertical driving force, and an upper electrode layer 414 that is stacked on the piezoelectric material layer 413 and provides a piezoelectric voltage to the piezoelectric material layer 413.

In addition, the element 410 is stacked on the right end of the lower support 411, and is laminated on the lower electrode layer 412 'and the lower electrode layer 412' for providing a piezoelectric voltage. A piezoelectric material layer 413 'that contracts and expands to generate a vertical driving force, and an upper electrode layer 414' that is stacked on the piezoelectric material layer 413 'and provides a piezoelectric voltage to the piezoelectric material layer 413'. Doing.

In addition, Korean Patent Application No. P2003-077389 describes the derived type in addition to the depression type described above.

On the other hand, the optical modulator of the type described in the patent of Bloom, Samsung Electro-Mechanics, etc. can be used as an element for displaying an image. In this case, at least two adjacent elements may form one pixel. Of course, three may be one pixel, four may be one pixel, or six may be one pixel.

However, optical modulators of the kind described in the patents of Bloom, Samsung Electro-Mechanics, etc. have certain limitations in achieving miniaturization. That is, no matter how small the width of the element of the optical modulator can be less than 3um, there is a limit that the distance between the element and the element can not be smaller than 0.5um.

In addition, since at least two or more elements are required to construct a diffractive pixel using such elements, there is a limit in miniaturization of the device.

In order to solve this problem, the "hybrid optical modulator" of Patent Application No. 2004-29925 discloses an optical modulator that enables the miniaturization by forming a plurality of irregularities in the micromirror layer.

The disclosed hybrid optical modulator has a plurality of irregularities on top of the micro mirror layer for reflecting and diffracting incident light. Each of the uneven parts is a rectangular columnar shape (bar shape), and is arranged to be spaced apart at regular intervals (for example, the same width as the uneven part width) along a transverse side across the recessed part of the element.

Each uneven portion is composed of an uneven support having a lower surface attached to the upper part of the micromirror layer of the element, and a uneven mirror layer laminated on the upper part thereof and reflecting and diffracting incident light.

In this case, the micromirror layer of the element between the uneven mirror layer and the uneven part of one of the uneven parts constitutes one pixel.

On the other hand, unlike the prior art disclosed in the above, it will be good to form the concave-convex mirror layer formed in the concave-convex portion in the form (embedded) in the element.

Accordingly, the present invention has been made to solve the above problems, an embedded diffraction optical modulator in which the upper mirror layer and the lower mirror layer to form a pixel by forming a mirror layer in the form of a double embedded element It is about.

The present invention for achieving the above object is a substrate having an insulating layer formed on the surface; And a central micropart positioned away from the substrate, both ends of which are attached to the substrate, and having a double micro mirror layer having a predetermined step so as to diffract the incident light. And an element having a pair of piezoelectric layers, wherein the element is driven by shrinkage expansion of the piezoelectric layer.

Moreover, this invention is the board | substrate with which the insulating layer is formed in the surface; A lower electrode layer stacked on the substrate; And a central part is spaced apart from the lower electrode layer stacked on the substrate, and both ends are attached to the substrate, and a double micro mirror layer having a predetermined step is provided therein to diffract incident light. And an element having an upper electrode layer corresponding to the lower electrode layer, wherein the lower electrode layer and the upper electrode layer provide a driving force to the element by an electrostatic force.

Moreover, this invention is the board | substrate with which the insulating layer is formed in the surface; An element having a central portion spaced apart from the substrate, both ends of which are attached to the substrate, and having a double micro mirror layer having a predetermined step so as to diffract incident light; And electromagnetic driving means for providing a vertical driving force to the element.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings of FIG. 5.

5 is a cut plane of an embedded optical modulator according to a first embodiment of the present invention.

Referring to the drawings, the embedded optical modulator according to the first exemplary embodiment of the present invention is positioned apart from the silicon substrate 501 and the silicon substrate 501 to provide the vertical driving space of the element 510 in the central portion thereof. The portion located in the recess of the silicon substrate 501 is movable up and down, and the mirror layers 512, 514a, 514b, and 514c are formed as a double layer so that the upper mirror layers 514a, 514b, and 514c and the lower mirror layer 512 are formed. It consists of the element 510 which comprises a pixel.

Here, the surface of the silicon substrate 501 includes an insulating layer 502 formed by a thermal oxidation method or the like, and the insulating layer 502 provides electrical insulation between the silicon substrate 501 and the element 510.

In addition, the silicon substrate 501 has a central portion deeply etched by wet etching or dry etching to form a depression, which provides a driving space when the central portion of the element 510 is vertically driven. That is, the lower surface of the element 510 is attached to both sides beyond the depression of the silicon substrate 501 so that the portion corresponding to the depression is spaced apart from the depression so that the depression provides driving space when the element 510 is driven up and down. do.

On the other hand, the element 510 is attached to the lower surface of the left and right sides on both side ends beyond the depression of the silicon substrate 501, the portion outside the depression is firmly fixed to the silicon substrate 501 and has a certain degree of rigidity The lower support part 511 is provided so that the part corresponding to the recessed part of the board | substrate 501 can continue to maintain the state spaced apart from the recessed part at predetermined distance.

At this time, the material constituting the lower support 511 may be Si oxide (for example, SiO2, etc.), Si nitride series (for example, Si3N4, etc.), ceramic substrate (Si, ZrO2, Al2O3, etc.), Si carbide, and the like. . The lower support 511 may be omitted as necessary.

In addition, a lower mirror layer 512 is stacked on the lower support 511, and is stacked in an unseparated state in the first embodiment of the present invention. As the material of the lower mirror layer 512, a light reflection material such as Ti, Cr, Cu, Ni, Al, Au, Ag, Pt, Au / Cr, or the like is used.

The light transmissive material layer 513 is stacked on the lower mirror layer 512, and the light transmissive material layer 513 transmits incident light so that the light can reach the lower mirror layer 512. Here, glass, a polymer, or the like may be used as the light transmissive material used for the light transmissive material layer 513.

Next, a plurality of upper micromirrors 514a, 514b, and 514c having a step from the lower micromirror layer 512 is inserted into the light transmissive material layer 513, wherein the plurality of upper micromirrors 514a, 6, it can be seen that the element 510 is composed of a plurality of separate mirrors 514a, 514b, and 514c at right angles to the direction crossing the depression of the silicon substrate 501. In this case, the distance between the mirrors of the plurality of upper micromirrors 514a, 514b, and 514c may maintain the same distance as the width of the mirror.

In this way, a portion corresponding to a portion between one mirror of the plurality of upper micromirrors 514a, 514b and 514c and the mirror of the plurality of upper micromirrors 514a, 514b and 514c in the lower micromirror layer 512. The lower micro mirror layer 512 may constitute one pixel. Of course, the pixel requires at least two stepped mirrors, but three, four, six, etc. may be used to increase the intensity of the diffracted light. In this case, the plurality of upper micromirrors 514a, 514b, and 514c may be used. This need is addressed by using one mirror and its adjacent mirror, and using the lower mirror layer 512 corresponding to the portion between the mirrors of the plurality of upper micromirrors 514a, 514b, and 514c in the lower mirror layer 512. Can satisfy.

The interlayer spacing of the upper micromirrors 514a, 514b and 514c and the lower micromirror layer 512 is given by the following equation (1).

D = λ / 4 * x

Where D defines the interlayer spacing, and x is an integer or not an integer. When x is an integer, it is used when the lower support 511 is firm, that is, when the distance between the mirrors of the upper micromirrors 514a, 514b and 514c and the lower micromirror layer 512 is fixed. Used when 511 is not hard and can be bent. The bent here refers to the bending of the upper micromirrors 514a, 514b, and 514c and the lower micromirror layer 512. The interlayer spacing becomes an odd multiple of λ / 4 depending on the degree of bending, thereby generating diffracted light. do.

As the material of the lower micromirror layer 512, a light reflection material such as Ti, Cr, Cu, Ni, Al, Au, Ag, Pt, Au / Cr, or the like is used.

Meanwhile, piezoelectric layers 520 and 520 ′ are formed at left and right sides of the light transmissive material layer 513 to provide driving force to the element 510. At this time, the piezoelectric layers 520 and 520 'are piezoelectric materials generating vertical driving force due to left and right contraction when voltage is applied to the lower electrode layers 521 and 521' for providing power to the piezoelectric material layers 522 and 522 '. And an upper electrode layer 523 for supplying power to the layers 522 and 522 'and the piezoelectric material layers 522 and 522'.

In this case, Pt, Ta / Pt, Ni, Au, Al, RuO2, etc. may be used as electrode materials of the lower electrodes 521 and 521 ', and are deposited by a sputter or evaporation method in a range of 0.01-3 μm.

The piezoelectric materials used for the piezoelectric material layers 522 and 522 'may use both upper and lower piezoelectric materials and left and right piezoelectric materials, and may use piezoelectric materials such as PzT, PNN-PT, ZnO, and Pb, Zr, Zn or For piezoelectric electrolytic materials containing at least one element, such as titanium.

At this time, the electrode material of the upper electrode layers 523 and 523 'may be Pt, Ta / Pt, Ni, Au, Al, RuO2, or the like, and may be formed by a sputter or evaporation method in a range of 0.01-3 μm.

7 is a cross-sectional view of an embedded diffractive optical modulator according to a second embodiment of the present invention. In the second embodiment of Fig. 7, the lower mirror is formed by a plurality of mirrors 712a and 712b separated from each other.

That is, in the second embodiment of FIG. 7, unnecessary parts are removed from the lower mirror layer of the first embodiment so that a plurality of mirrors 712a and 712b are separated, and the first mirror is formed in the process of forming the lower mirror. Unnecessary portions of the lower micromirror layer of the embodiment are removed to prepare the plurality of mirrors 712a and 712b in a separated state.

Referring to the drawings, the embedded diffraction optical modulator according to the second embodiment of the present invention is composed of a silicon substrate 701 and an element 710.

Here, the surface of the silicon substrate 701 has an insulating layer 702 formed by a thermal oxidation method or the like, and the silicon substrate 701 has a central portion deeply etched by wet etching or dry etching to form a depression. There is a depression such that the element 710 provides a drive space for the vertical drive.

On the other hand, the element 710 is attached to the lower surface of the left and right sides on both side ends beyond the depression of the silicon substrate 701, the portion outside the depression is firmly fixed to the silicon substrate 701 and has a certain degree of rigidity The lower support part 711 is provided so that the part corresponding to the recessed part of the board | substrate 701 can continue to maintain the state spaced apart from the recessed part at predetermined distance.

In addition, a plurality of lower mirrors 712a and 712b are stacked on the lower support 711, and in the second embodiment of the present invention, a plurality of mirrors 712a and 712b are disposed in a separated state by removing unnecessary portions. have. At this time, the interval may be equal to the width of the mirror. Of course, the plurality of lower mirrors 712a and 712b may be inserted into the light transmissive material layer 713 at a predetermined distance from the lower support 711.

The light transmissive material layer 713 is stacked on the lower mirrors 712a and 712b, and the light transmissive material layer 713 transmits incident light so that the light may reach the plurality of lower mirrors 712a and 712b. To help.

Next, a plurality of upper micromirrors 714a, 714b, and 714c are formed on the light-transmitting material layer 713, wherein the inserted upper micromirrors 714a, 714b, and 714c have an element having a silicon substrate. It can be seen that it consists of a plurality of separate mirrors at right angles to the direction across the recess. At this time, the interval between the mirrors of the plurality of separate mirrors of the upper micro mirror may maintain the same interval as the width of the mirror.

In this way, one pixel between one mirror of the upper micromirrors 714a, 714b, and 714c and a mirror located at a portion between the mirrors of the upper micromirrors 714a, 714b, and 714c in the lower micromirrors 712a and 712b. Can be configured. Of course, the pixel requires at least two stepped mirrors, but three, four, six, etc. can be used to increase the intensity of the diffracted light, in which case one of the upper micro mirrors 714a, 714b, 714c is used. Mirrors and mirrors adjacent thereto, which are located between the mirrors of the plurality of upper micromirrors 714a, 714b, 714c and the adjacent mirrors in the lower mirrors 712a, 712b, satisfy this need. It can be used to make.

The interlayer spacing of the upper micromirrors 714a, 714b, and 714c and the lower micromirrors 712a and 712b must satisfy Equation (1) as well.

Meanwhile, piezoelectric layers 720 and 720 ′ are formed on the left and right sides of the light transmissive material layer 713 to provide driving force to the element 710. At this time, the piezoelectric layers 720 and 720 'generate piezoelectric materials that generate vertical driving force due to left and right contraction when a voltage is applied to the lower electrode layers 721 and 721' for providing power to the piezoelectric material layers 722 and 722 '. Layers 722 and 722 ', and piezoelectric material layers 722 and 722' to form upper electrode layers 723 and 723 'for supplying power.

8 is a cross-sectional view of an embedded optical modulator according to a third exemplary embodiment of the present invention.

Referring to the drawings, in the third embodiment of the present invention, the direction in which the mirrors forming the upper micromirror layers 814a and 814b are arranged in the same direction as the direction in which the elements cross the recesses in comparison with the first and second embodiments. Is that it is.

Referring to the drawings, the embedded diffraction optical modulator according to the third embodiment of the present invention includes a silicon substrate 801 and an element 810.

The surface of the silicon substrate 801 is provided with an insulating layer 802 formed by a thermal oxidation method or the like.

On the other hand, the element 810 is provided with a lower support 811, the lower micro mirror layer 812 is stacked on the lower support 811, in the third embodiment of the present invention is laminated without being separated have.

In addition, a light transmissive material layer 813 is stacked on the lower micro mirror layer 812, and the light transmissive material layer 813 transmits incident light so that the light may reach the lower micro mirror layer 812. do.

Next, the upper micromirror layers 814a and 814b are inserted into the light transmissive material layer 813. In this case, the inserted upper micromirror layers 814a and 814b have an element 810 as a silicon substrate (see FIG. 9). It can be seen that it is composed of a plurality of separate mirrors 814a and 814b in the same direction as the direction crossing the depression of 801. In this case, the interval between the mirrors of the plurality of separate mirrors of the upper micromirrors 814a and 814b may maintain the same interval as the width of the mirror.

Thus, the lower micromirror layer 812 in a portion corresponding to the portion between one mirror of the upper micromirrors 814a and 814b and the mirror of the upper micromirrors 814a and 814b in the lower micromirror layer 812. This single pixel can be constituted. Of course, the pixel requires at least two stepped mirrors, but three, four, six, etc. may be used to increase the intensity of the diffracted light, in which case one mirror of the upper micro mirrors 814a and 814b is used. This need can be met by using a mirror adjacent thereto and using a lower micromirror layer 812 corresponding to the portion between the mirrors of the upper micromirrors 814a and 814b in the lower micromirror layer 812.

The interlayer spacing between the upper micromirror layers 814a and 814b and the lower micromirror layer 812 satisfies Equation (1).

In addition, piezoelectric layers 820 and 820 ′ are formed at left and right sides of the light transmissive material layer 813 to provide driving force to the element 810. At this time, the piezoelectric layers 820 and 820 'are formed of lower electrode layers 821 and 821', piezoelectric material layers 822 and 822 ', and upper electrode layers 823 and 823'.

Meanwhile, in the third embodiment of the present invention, the lower micromirror layer 812 is described as being not separated into a plurality of mirrors, but as in the second embodiment, the lower micromirror layer 812 is formed of a plurality of mirrors. It can also be implemented to exist in a separate state.

10 is a cross-sectional view of an embedded optical modulator according to a fourth embodiment of the present invention.

Referring to the drawings, the embedded optical modulator according to the fourth exemplary embodiment of the present invention has a silicon substrate 1001 having a insulating layer 1002 formed on a surface thereof, a rod shape, and a center portion thereof is spaced apart from the silicon substrate 1001. The lower ends of both ends are attached to the silicon substrate 1001, and the portions spaced apart from each other by the predetermined distance from the silicon substrate are movable up and down, and the upper micro mirrors 1014a and 1014b are provided with double layers. The lower micromirror layer 1012 is composed of an element 1010 forming a pixel.

The element 1010 has a rod shape, and a center portion thereof is spaced apart from the silicon substrate 1001, and lower ends of both ends are attached to the silicon substrate 1001, and portions spaced apart from the silicon substrate 1001 are disposed. The upper and lower lower supporters 1011 are provided.

The material constituting the lower support 1011 may be Si oxide (for example, SiO2), Si nitride series (for example, Si3N4, etc.), ceramic substrate (Si, ZrO2, Al2O3, etc.), Si carbide, or the like. The lower support 1011 can be omitted as necessary.

The element 1010 includes a lower micromirror layer 1012 stacked on the lower support 1011, and the lower micromirror layer 1012 includes Ti, Cr, Cu, Ni, Al, Light reflecting materials such as Au, Ag, Pt, Au / Cr and the like are used.

Next, a light transmissive material layer 1013 is stacked on the lower micromirror layer 1012 to transmit incident light to the lower micromirror layer 1012. The material of the light transmissive material layer 1013 is glass, epoxy, or the like.

A plurality of upper micromirrors 1014a and 1014b are stacked on the light transmissive material layer 1013, and the plurality of separate micromirrors 1014a and 1014b are aligned at right angles to the horizontal axis of the lower support 1011. It is.

The light transmissive material layer 1013 is stacked on the upper micromirror layers 1014a and 1014b to transmit incident light to be incident on the upper micromirror layers 1014a and 1014b and the lower micromirror layer 1012.

On the other hand, piezoelectric layers 1020 are stacked on both sides of the light transmissive material layer 1013, and the piezoelectric layers 1020 and 1020 'are provided with lower electrode layers 1021 and 1021', piezoelectric material layers 1022 and 1022 ', and an upper portion. Electrode layers 1023 and 1023 'are provided.

When voltage is applied to the piezoelectric layers 1020 and 1020 ', vertical driving force is generated in the element 1010 by left and right contraction motion.

Meanwhile, in the fourth exemplary embodiment of the present invention, the lower micromirrors have been described in a state in which the lower micromirrors are not separated into a plurality of mirrors, but alternatively, an unnecessary portion may be removed.

In addition, in the fourth embodiment of the present invention, a plurality of micromirrors of the upper micromirrors are formed to be arranged along the horizontal direction, but may be formed in parallel.

In this case, of course, a plurality of lower micro mirror layers may be separated to form a form in which unnecessary parts are removed.

11 is a cross-sectional view of an embedded diffractive optical modulator according to a fifth embodiment of the present invention.

Referring to the drawings, the embedded diffraction optical modulator according to the fifth embodiment of the present invention is spaced apart from the silicon substrate 1101 and the silicon substrate 1101 for providing the vertical driving space of the element 1110 in the center portion. The upper and lower mirror layers 1115a, 1115b, 1115c, and 1115d and the lower mirror layer 1113 constitute pixels. It consists of an element 1110.

Here, the surface of the silicon substrate 1110 includes an insulating layer 1102 formed by a thermal oxidation method or the like, and a lower electrode layer 1103 is formed on the insulating layer 1102. In the element 1110, an upper electrode layer 1112 corresponding to the lower electrode layer 1103 is formed on the insulating layer 1111, and the lower electrode layer 1113 and the upper electrode layer 1112 cooperate with each other to form an element due to electrostatic force. A vertical driving force of 1110 is generated. That is, the fifth embodiment, unlike the first to fourth embodiments, provides the up and down driving force to the element 1110 by an electrostatic driving method. At this time, the electrode material used may be Pt, Ta / Pt, Ni, Au, Al, RuO 2 and the like, and is formed by a method such as sputter or evaporation in the 0.01 ~ 3㎛ range.

On the other hand, the element 1110 is attached to the lower surface of the left and right sides on both side ends beyond the depression of the silicon substrate 1101, and the portion outside the depression is firmly fixed to the silicon substrate 1101 and has a certain degree of rigidity. A lower support for selectively maintaining a state in which a portion corresponding to the depression of the substrate 1101 is spaced a predetermined distance from the depression may be provided.

At this time, the material constituting the lower support may be Si oxide (for example, SiO2, etc.), Si nitride series (for example, Si3N4, etc.), a ceramic substrate (Si, ZrO2, Al2O3, etc.), Si carbide and the like. This lower support can be omitted if necessary.

In addition, a lower micromirror layer 1113 is stacked on the upper electrode layer 1112, and is not stacked in the fifth embodiment of the present invention. As the material of the lower micromirror layer 1113, light reflecting materials such as Ti, Cr, Cu, Ni, Al, Au, Ag, Pt, Au / Cr, and the like are used.

The light transmissive material layer 1114 is stacked on the lower micromirror layer 1113, and the light transmissive material layer 1114 transmits incident light so that the light can reach the lower micromirror layer 1112. do. Here, as the light transmissive material used in the light transmissive material layer 1114, glass, a polymer, or the like may be used.

Next, a plurality of upper micromirrors 1115a, 1115b, and 1115c are formed on the light-transmissive material layer 1114. The upper micromirrors 1115a, 1115b, and 1115c formed at this time may have an element 1110. It can be seen that it is composed of a plurality of separate mirrors along the direction crossing the depression of the silicon substrate 1101. In this case, the interval between the mirrors of the plurality of separate mirrors of the upper micromirrors 1115a, 1115b, 1115c, and 1115d may maintain the same interval as the width of the mirror.

As a result, a portion of one mirror of the plurality of upper micromirrors 1115a, 1115b, 1115c, and 1115d and a mirror of the plurality of upper micromirrors 1115a, 1115b, 1115c, and 1115d in the lower micromirror layer 1112 may be used. The micromirror layer 1112 in the corresponding portion may constitute one pixel. Of course, the pixel requires at least two stepped mirrors, but three, four, six, etc. may be used to increase the intensity of the diffracted light, in which case the upper micro mirror layers 1115a, 1115b, 1115c, and 1115d are used. One mirror of the mirror and an adjacent mirror thereof, and a lower micromirror 1112 corresponding to a portion between the mirrors of the upper micromirror layers 1115a, 1115b, 1115c, and 1115d in the lower micromirror layer 1112. This need can be met.

At this time, the interlayer spacing between the upper micromirrors 1115a, 1115b, 1115c, and 1115d and the lower micromirror layer 1112 satisfies Equation (1).

 As the material of the lower micromirror layer 1112, light reflecting materials such as Ti, Cr, Cu, Ni, Al, Au, Ag, Pt, Au / Cr, and the like are used.

Meanwhile, the embedded optical modulator according to the fifth embodiment of the present invention may be implemented such that the upper micro mirror layer is formed in the horizontal direction but is formed in the vertical direction, and may be implemented as a plurality of mirrors from which unnecessary parts are removed from the lower micro mirror layer. have.

In addition, although the recessed type of the embedded optical modulator has been described in the fifth embodiment of the present invention, the derived type may be manufactured in the same structure.

12 is a cross-sectional view of an embedded diffractive optical modulator according to a sixth embodiment of the present invention.

Referring to the drawings, the embedded optical modulator according to the sixth embodiment of the present invention is spaced apart from the silicon substrate 1201 and the silicon substrate 1201 for providing a vertical drive space of the element 1210 in the center portion. And the portion located in the depression of the silicon substrate 1201 can be moved up and down, and the mirror is formed of a double layer so that the upper mirror layers 1214a, 1214b, 1214c, 1214d and the lower mirror layer 1212 constitute pixels. It consists of 1210.

Here, the surface of the silicon substrate 1201 includes an insulating layer 1202 formed by a thermal oxidation method or the like, and a lower electrode layer 1203 is formed on the insulating layer 1202. In the element 1210, an upper electrode layer 1213 corresponding to the lower electrode layer 1203 is formed as an optical transmission electrode between the lower micro mirror layer 1212 and the upper micro mirror layers 1214a, 1214b, 1214c, and 1214d. The lower electrode layer 1203 and the upper electrode layer 1213 cooperate with each other to generate the vertical driving force of the element 1210 by the electrostatic force. That is, the sixth embodiment provides the vertical driving force to the element 1210 by the electrostatic driving method as in the fifth embodiment. In this case, Pt, Ta / Pt, Ni, Au, Al, RuO2, etc. may be used as the lower electrode material, and may be formed by a sputter or evaporation method in a range of 0.01-3 μm, and the upper electrode material may be formed of ITO or the like. to be.

On the other hand, the element 1210 is attached to the lower surface of the left and right sides on both side ends beyond the depression of the silicon substrate 1201, and the portion outside the depression is firmly fixed to the silicon substrate 1201 and has a certain degree of rigidity. The lower support 1211 may be selectively provided so that the portion corresponding to the depression of the substrate 1201 can continuously maintain the state spaced apart from the depression by a certain distance.

In this case, the material constituting the lower support 1211 may be Si oxide (for example, SiO2), Si nitride series (for example, Si3N4, etc.), ceramic substrate (Si, ZrO2, Al2O3, etc.), Si carbide, or the like. . The lower support 1211 can be omitted as necessary.

In addition, the lower mirror layer 1212 is stacked on the lower support 1211, and is stacked in an unseparated state in the sixth embodiment of the present invention. As the material of the lower mirror layer 1212, light reflection materials such as Ti, Cr, Cu, Ni, Al, Au, Ag, Pt, Au / Cr, and the like are used.

In addition, an upper electrode layer 1213 is stacked on the lower mirror layer 1212, and the upper electrode layer 1213 transmits light incident to the optical transmission electrode to allow the light to reach the lower mirror layer 1212.

Next, upper micro mirror layers 1214a, 1214b, 1214c, and 1214d are formed on the upper electrode layer 1213, and the upper micromirror layers 1214a, 1214b, 1214c, and 1214d of the formed element 1210 are formed of silicon. It can be seen that it is composed of a plurality of separate mirrors perpendicular to the direction crossing the recessed portion of the substrate 1201. In this case, the interval between the mirrors of the plurality of separate mirrors of the upper micromirrors 1214a, 1214b, 1214c, and 1214d may maintain the same interval as the width of the mirror.

This corresponds to the portion between one mirror of the upper micromirror layers 1214a, 1214b, 1214c, and 1214d and the mirror of the upper micromirror layers 1214a, 1214b, 1214c, and 1214d in the lower micromirror layer 1212. The micro mirror layer 1212 in the portion can constitute one pixel. Of course, the pixel requires at least two stepped mirrors, but three, four, six, etc. may be used to increase the intensity of the diffracted light, in which case the upper micro mirror layers 1214a, 1214b, 1214c, and 1214d. Using one mirror of the mirror and adjacent mirrors, and using the lower mirror layer 1212 corresponding to the portion between the mirrors of the upper micromirror layers 1214a, 1214b, 1214c, and 1214d in the lower mirror layer 1212. Can meet your needs.

The interlayer spacing between the upper mirror layers 1214a, 1214b, 1214c, and 1214d and the lower mirror layer 1212 satisfies (Equation 1).

 As the material of the lower mirror layer 1212, light reflection materials such as Ti, Cr, Cu, Ni, Al, Au, Ag, Pt, Au / Cr, and the like are used.

The light transmissive material 1215 is stacked on the upper micromirror layers 1214a, 1214b, 1214c and 1214d, and the light transmissive material layer 1215 is formed of glass, a polymer, or the like.

Meanwhile, although the state in which the lower micromirror layer is not separated has been described, it may be configured in a separated form, and may be implemented to be aligned in the vertical direction.

In addition, although the depression type has been described herein, the derived type may be equally implemented.

Meanwhile, although a method of obtaining a driving force using an electrostatic force and a piezoelectric material has been described herein, a method of obtaining a driving force using a magnetic force can also be used.

Also, here the embedded mirror is square, but there are many ways, such as circle, triangle.

The present invention as described above has the effect of enabling the fabrication of the embedded diffraction optical modulator to improve the precision and to enable the fabrication of the optical modulator without being affected by changes in the external environment.

What has been described above is only one embodiment for implementing the embedded diffraction optical modulator according to the present invention, and the present invention is not limited to the above-described embodiment, and as claimed in the following claims, the gist of the present invention Without departing from the technical spirit of the present invention to the extent that any person of ordinary skill in the art to which the present invention pertains various modifications can be made.

1 illustrates a prior art electrostatic grating light modulator.

2 is a diagram showing that the prior art electrostatic grating light modulator reflects incident light without being deformed.

3 is a diagram illustrating diffraction of incident light in a state where a prior art grating light modulator is deformed by electrostatic force;

4 is a side view of a diffractive thin film piezoelectric micromirror with depressions having a piezoelectric material in the prior art;

5 is a side cutaway view of an embedded diffractive optical modulator according to a first embodiment of the present invention;

FIG. 6 is a cross-sectional view taken along line AA ′ of FIG. 5.

7 is a side cross-sectional view of an embedded diffractive optical modulator according to a second embodiment of the present invention.

FIG. 8 is a cross-sectional view taken along line AA ′ of FIG. 7.

9 is a side cutaway view of an embedded diffractive optical modulator according to a third embodiment of the present invention.

10 is a side cross-sectional view of an embedded diffractive optical modulator according to a fourth embodiment of the present invention.

11 is a side cross-sectional view of an embedded diffractive optical modulator according to a fifth embodiment of the present invention.

12 is a side cross-sectional view of an embedded diffractive optical modulator according to a sixth embodiment of the present invention.

Claims (16)

A substrate having an insulating layer formed on its surface; And A central portion is located away from the substrate, both ends are attached to the substrate, and a double micromirror layer having a predetermined step is provided therein so as to diffract incident light, and a pair is provided at both ends. An element having a piezoelectric layer of And the element is driven by shrinkage expansion of the piezoelectric layer. The method of claim 1, And the substrate has a depression for providing an air space, and the element is spaced apart from the depression by a predetermined distance to secure a driving space. The method of claim 1, And the surface of the substrate is flat, and a central portion of the element is drawn at a predetermined interval from the substrate to secure a driving space. The method of claim 1, The element is A lower micro mirror layer stacked on the upper electrode layer and reflecting incident light; A light transmissive material layer laminated on the lower micro mirror layer and transmitting incident light; An upper micro mirror layer embedded in the light transmissive material layer to have a predetermined step with the lower micro mirror layer, the upper micro mirror layer having a plurality of micro mirrors having a predetermined interval reflecting incident light; And And a pair of piezoelectric layers which are separated and stacked at both ends of the light transmissive material layer and provide a vertical driving force by shrinkage expansion. The method of claim 4, wherein And the lower micromirror layer is stacked on the upper electrode layer and comprises a plurality of micromirrors having a predetermined interval reflecting incident light. The method according to claim 4 or 5, The plurality of micro mirrors of the upper micro mirror layer, And the elements are aligned in the same direction as the direction across the substrate. The method according to claim 4 or 5, The plurality of micro mirrors of the upper micro mirror layer, And the elements are aligned in a direction perpendicular to a direction crossing the substrate. A substrate having an insulating layer formed on its surface; A lower electrode layer stacked on the substrate; And The central portion is spaced apart from the lower electrode layer stacked on the substrate, and both ends are attached to the substrate, and a double micro mirror layer having a predetermined step is provided therein to diffract incident light. And an element having an upper electrode layer corresponding to the lower electrode layer, And the lower electrode layer and the upper electrode layer provide a driving force to the element by electrostatic force. The method of claim 8, And the substrate has a depression for providing an air space, and the element is spaced apart from the depression by a predetermined distance to secure a driving space. The method of claim 8, And the surface of the substrate is flat, and a central portion of the element is drawn at a predetermined interval from the substrate to secure a driving space. The method of claim 8, The element is An upper electrode layer generating an electrostatic force when a voltage is applied; A lower micro mirror layer stacked on the upper electrode layer and reflecting incident light; A light transmissive material layer laminated on the lower micro mirror layer and transmitting incident light; And An embedded diffractive light modulator embedded in the light transmissive material layer so as to have a predetermined step with the lower micromirror layer, and including an upper micromirror layer having a plurality of micromirrors having a predetermined distance reflecting incident light; . The method of claim 8, The element is An upper electrode layer generating an electrostatic force when a voltage is applied; A lower micromirror layer stacked on the upper electrode layer, the lower micromirror layer having a plurality of micromirrors having a predetermined interval reflecting incident light; A light transmissive material layer laminated on the lower micro mirror layer and transmitting incident light; And An embedded diffractive light modulator embedded in the light transmissive material layer so as to have a predetermined step with the lower micromirror layer, and including an upper micromirror layer having a plurality of micromirrors having a predetermined distance reflecting incident light; . The method of claim 8, The element is A lower mirror layer reflecting incident light; A light transmissive material layer laminated on the lower mirror layer and transmitting incident light; An upper micro mirror layer embedded in the light transmissive material layer so as to have a predetermined step with the lower mirror layer, the upper micro mirror layer having a plurality of micro mirrors having a predetermined interval reflecting incident light; And And an upper electrode layer of a transparent electrode material stacked between the lower mirror layer and the upper micromirror layer. The method according to claim 11, wherein The plurality of micro mirrors of the upper mirror layer, And the elements are aligned in the same direction as the direction across the substrate. The method according to claim 11, wherein The plurality of micro mirrors of the upper micro mirror layer, And the elements are aligned in a direction perpendicular to a direction crossing the substrate. A substrate having an insulating layer formed on its surface; An element having a central portion spaced apart from the substrate, both ends of which are attached to the substrate, and having a double micro mirror layer having a predetermined step so as to diffract incident light; And Embedded diffraction light modulator comprising an electromagnetic drive means for providing a vertical driving force to the element.