KR101041886B1 - Corner cube retroreflector and method for fabricating the same - Google Patents

Abstract

Corner cube type retroreflectors and methods of making the same are disclosed. A substrate having a rectangular cavity region formed in a central region, four rectangular reflective reflectors positioned at predetermined intervals in a cross shape in the cavity region, and each corner and each corner of the cavity region; A driving piezoelectric cantilever for connecting the first edges of the adjacent driving reflectors, a fixed piezoelectric cantilever for connecting the second edges and the third edges of the driving reflecting mirrors to adjacent portions of the substrate, and a predetermined cross shape A corner including a fixed reflector formed in a direction perpendicular to one surface of the substrate on a gap and having a predetermined protrusion, and a holder formed on the substrate in combination with the protrusion to fix the fixed reflector to the substrate. Construct a cube retroreflector. According to the corner cube type retroreflector as described above, two fixed piezoelectric cantilevers provided in addition to the driving piezoelectric cantilever serve as a rotation axis of the driving reflector, thereby minimizing initial deflection of the driving reflector and improving flatness.

Corner cube, reflector, piezoelectric, cantilever, retroreflector, cavity

Description

Corner cube retroreflector and its manufacturing method {CORNER CUBE RETROREFLECTOR AND METHOD FOR FABRICATING THE SAME}

The present invention relates to a retroreflector and a method of manufacturing the same, and more particularly, to a corner cube type retroreflector and a method of manufacturing the same.

A corner cube retroreflector, a type of micro-opto-electro mechanical system (MOEMS), is a microscopic optical component that is applied to optical communication in free space.

The corner cube type retroreflector mainly reflects the light used for optical communication in a desired direction or controls the reflectance of the light to irradiate the required amount of light. The corner cube type retroreflectors are difficult to eavesdropping and are able to be kept secret. Therefore, researches on the development of optical tags for military identification of PIAs are mainly conducted.

The corner cube type retroreflector has an electrostatic force method, an electromagnetic force method, and a piezoelectric method depending on the driving method. The electrostatic force method has difficulty in precise control and requires high voltage, and the electromagnetic force method is difficult to miniaturize due to the magnetic material, while the piezoelectric method uses piezoelectric elements, so it can operate at low voltage and can be miniaturized. have.

1 is a perspective view of a driving reflector structure of a corner cube type retro reflector according to a conventional piezoelectric method. The drive reflector structure 100 of the cube retroreflector according to the piezoelectric method of FIG. 1 has a drive piezoelectric cantilever 130 positioned only at the side of the drive reflector 120 to prevent the occurrence of a communication shadow area. Although it has the advantage of reducing, there is a disadvantage that the deflection of the drive reflector 120 occurs before voltage is applied because of the initial deformation of the drive piezoelectric cantilever 130. That is, it becomes difficult to control the direction of the light reflected by the corner cube retroreflector.

On the other hand, the corner cube type retroreflector according to the conventional piezoelectric method was mainly manufactured using surface micro-machining. When applying the surface micromachining technology, three reflectors of the corner cube type retroreflector are used. Each must be raised and assembled by hand. This approach has the disadvantage that the process is complex and requires high technology.

In order to overcome this disadvantage, a manufacturing method using a bulk micro-machininig has recently been considered. In the case of using the body microfabrication technology, the fixed reflector positioned at the top of the corner cube retroreflector and the drive reflector positioned at the bottom are separately manufactured, and then the fixed reflector and the drive reflector are assembled. By the way, in such a body microfabrication technique, in order to form the corner cube shape which can precisely control the direction of light, it is an important subject to align correctly the upper fixed reflector and the lower driving reflector.

An object of the present invention is to provide a corner cube type retro reflector.

Another object of the present invention is to provide a method for producing a corner cube type retro reflector.

Corner cube-type retroreflector for achieving the above object of the present invention, the substrate is formed with a rectangular cavity region in the center region, and four quadrangles positioned at predetermined intervals of the cross shape in the cavity region With a driving reflector of the shape. A driving piezoelectric cantilever for connecting each corner of the cavity region and the first edge of each driving reflector adjacent to each corner, and connecting the second and third edges of the driving reflector that face each other with adjacent portions of the substrate, respectively. A fixed piezoelectric cantilever, a fixed reflector formed in a direction perpendicular to one surface of the substrate on a predetermined interval of the cross shape, and having a predetermined protrusion, and coupled with the protrusion to fix the fixed reflector to the substrate. It may be configured to include a holder formed on the substrate. Here, the driving piezoelectric cantilever is connected to the first edge of the driving reflector through a first hinge, and the fixed piezoelectric cantilever is connected to the second and third edges of the driving reflector through a second hinge and a third hinge. Each may be configured to be connected. The first hinge, the second hinge, and the third hinge may be configured as a meander type hinge or a straight type hinge. On the other hand, the drive piezoelectric cantilever is a corner cube type retroreflector, characterized in that each is driven individually.

In order to achieve the above object of the present invention, a method of manufacturing a drive reflector structure of a corner cube type retroreflector comprises the steps of forming a silicon nitride film on the first and second surfaces of the substrate, and formed on the first surface Forming a lower electrode material, a piezoelectric material, and an upper electrode material in order on the silicon nitride film, etching the lower electrode material, the piezoelectric material, and the upper electrode material to form a driving piezoelectric cantilever and a fixed piezoelectric cantilever; Forming a metal thin film for increasing the reflectance of the driving reflector on the silicon nitride film formed on the first surface, and four rectangular driving reflecting mirrors at predetermined center regions of the substrate at a predetermined interval of cross shape Dry etching the second surface to be formed; forming a holder on the first surface of the substrate; Etching to form a cavity in the second side of the central region and can be configured to include the step of driving the reflector, wherein the drive piezoelectric cantilever and release the fixing piezoelectric cantilever (release). The etching of the dry-etched central region to form a cavity to release the driving reflector, the driving piezoelectric cantilever, and the fixed piezoelectric cantilever may include forming a cavity by wet etching or dry etching the central region. It can be configured to. And etching the dry-etched central region to form a cavity to release the driving reflector, the driving piezoelectric cantilever, and the fixed piezoelectric cantilever, in the case of forming the cavity by wet etching the central region. Or it may be configured to wet etch using the TMAH method. Etching the dry etched central region to form a cavity to release the driving reflector, the driving piezoelectric cantilever, and the fixed piezoelectric cantilever may include a method of performing a DRIE method when dry etching the central region to form a cavity. It may be configured to dry etching using. Meanwhile, forming the silicon nitride film on the first and second surfaces of the substrate may be configured to form a low stress nitride film by low pressure chemical vapor deposition (LPCVD). And sequentially forming the lower electrode material, the piezoelectric material, and the upper electrode material on the silicon nitride film formed on the first surface, by sputtering titanium / platinum or platinum to form the lower electrode material or the upper electrode material. Can be. The forming of the lower electrode material, the piezoelectric material, and the upper electrode material in order on the silicon nitride film formed on the first surface may include forming a lead-zirconium-titanium composite oxide thin film in a sol-gel manner. It may be configured to form by deposition. The forming of the metal thin film for increasing the reflectance of the driving reflector on the silicon nitride film formed on the first surface may include depositing any one of gold, platinum, and aluminum in a lift-off manner. Can be configured. And forming the holder on the first surface of the substrate may be configured to form a holder using Su-8 material or CAR44 material.

In order to achieve the above object of the present invention, a method of manufacturing a drive reflector structure of a corner cube retroreflector includes the steps of forming an SOI layer on a first side of a substrate, and a lower electrode material on the formed SOI layer. Forming a piezoelectric material and an upper electrode material in order, etching the lower electrode material, the piezoelectric material, and the upper electrode material to form a driving piezoelectric cantilever and a fixed piezoelectric cantilever; Forming a metal thin film on the SOI layer to increase the reflectance of the driving reflector, and the second surface such that four rectangular driving reflectors are formed at a predetermined interval in a cross shape in a predetermined center region of the substrate; Dry etching, forming a holder on the SOI layer, and etching the second surface of the dry etched central region to form a cavity. And releasing the drive reflector, the drive piezoelectric cantilever and the fixed piezoelectric cantilever. The etching of the dry-etched central region to form a cavity to release the driving reflector, the driving piezoelectric cantilever, and the fixed piezoelectric cantilever may include forming a cavity by wet etching or dry etching the central region. It can be configured to. And etching the dry-etched central region to form a cavity to release the driving reflector, the driving piezoelectric cantilever, and the fixed piezoelectric cantilever, in the case of forming the cavity by wet etching the central region. Or it may be configured to wet etch using the TMAH method. Meanwhile, in the forming of the cavity by etching the dry-etched center region to release the driving reflector, the driving piezoelectric cantilever and the fixed piezoelectric cantilever, when the dry etching the center region to form a cavity, DRIE It may be configured to dry etching using the method. The forming of the SOI layer on the first surface of the substrate may be configured to form the SOI layer by a chemical-mechanical polishing (CMP) process. And sequentially forming the lower electrode material, the piezoelectric material and the upper electrode material on the formed SOI layer may be configured to sputter titanium / platinum or platinum to form the lower electrode material or the upper electrode material. And sequentially forming a lower electrode material, a piezoelectric material, and an upper electrode material on the formed SOI layer to be formed by depositing a lead-zirconium-titanium composite oxide thin film in a sol-gel manner. Can be. And forming a metal thin film on the SOI layer formed on the first surface to increase the reflectance of the driving reflector to deposit any one of gold, platinum, and aluminum in a lift-off manner. Can be. And forming a holder on the SOI layer may be configured to form a holder using Su-8 material or CAR44 material.

According to the corner cube type retroreflector as described above, two fixed piezoelectric cantilevers provided in addition to the driving piezoelectric cantilever serve as a rotation axis of the driving reflector, thereby minimizing initial deflection of the driving reflector and improving flatness. In addition, the fixed reflector is accurately aligned with the driving reflector by the holder provided in the substrate, thereby forming a corner cube shape capable of precisely controlling the direction of light. On the other hand, according to the manufacturing method of the corner cube-type retroreflector as described above, there is an effect that the process is very easy and simple.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. Like reference numerals are used for like elements in describing each drawing.

The terms first, second, A, B, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof described in the specification, and one or more other It is to be understood that the present invention does not exclude the possibility of the presence or the addition of features, numbers, steps, operations, components, parts, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

EMBODIMENT OF THE INVENTION Hereinafter, the structure of this invention is demonstrated.

The corner cube retroreflector according to the present invention includes a substrate having a rectangular cavity area formed in a central area, four rectangular shaped driving reflectors positioned at predetermined intervals in a cross shape in the cavity area, A driving piezoelectric cantilever for connecting each corner of the cavity region and the first edge of each of the driving reflectors adjacent to the corners, a second edge and a third edge of the driving reflecting mirror, and adjacent portions of the substrate, respectively; A fixed piezoelectric cantilever for connection, a fixed reflector formed in a direction perpendicular to one surface of the substrate on a predetermined interval of the cross shape, and having a predetermined protrusion, and coupled with the protrusion to fix the fixed reflector to the substrate. It may be configured to include a holder formed on the substrate. Here, the driving piezoelectric cantilever is connected to the first edge of the driving reflector through a first hinge, and the fixed piezoelectric cantilever is connected to the second and third edges of the driving reflector through a second hinge and a third hinge. Each may be configured to be connected. The first hinge, the second hinge, and the third hinge may be configured as a meander type hinge or a straight type hinge. On the other hand, the drive piezoelectric cantilever is a corner cube type retroreflector, characterized in that each is driven individually.

A method of manufacturing a driving reflector structure of a corner cube retroreflector according to the present invention comprises the steps of forming a silicon nitride film on the first and second surfaces of the substrate, and a lower electrode on the silicon nitride film formed on the first surface Forming a material, a piezoelectric material, and an upper electrode material in order; etching the lower electrode material, the piezoelectric material, and the upper electrode material to form a driving piezoelectric cantilever and a fixed piezoelectric cantilever; and formed on the first surface. Forming a metal thin film to increase the reflectance of the driving reflector on the silicon nitride film; and forming the four rectangular driving reflecting mirrors at predetermined intervals in the predetermined center region of the substrate at a predetermined interval of the cross shape. Dry etching a surface, forming a holder on the first surface of the substrate, and performing a dry etching on the second surface of the dry etched central region. Etched may be arranged to form a cavity that includes the step of driving said mirror, said driving piezoelectric cantilever and a fixed release the piezoelectric cantilever (release). The etching of the dry etched central region to form a cavity to release the driving reflector, the driving piezoelectric cantilever and the fixed piezoelectric cantilever may be configured to wet etch or dry etch the central region to form a cavity. Can be. The etching of the dry-etched central region to form a cavity to release the driving reflector, the driving piezoelectric cantilever, and the fixed piezoelectric cantilever may include forming a cavity by wet etching the central region to form a cavity. It may be configured to wet etch using. Etching the dry etched central region to form a cavity to release the driving reflector, the driving piezoelectric cantilever, and the fixed piezoelectric cantilever, when dry etching the central region to form a cavity, using a DRIE method It may be configured to etch. Meanwhile, forming the silicon nitride film on the first surface and the second surface of the substrate may be configured to form a low stress nitride film by low pressure chemical vapor deposition (LPCVD). The forming of the lower electrode material, the piezoelectric material, and the upper electrode material in order on the silicon nitride film formed on the first surface may include sputtering titanium / platinum (Ti / Pt) or platinum (Pt) to lower electrode material. Or to form an upper electrode material. The forming of the lower electrode material, the piezoelectric material, and the upper electrode material in order on the silicon nitride film formed on the first surface may include sol-gel forming a lead-zirconium-titanium (Pb-Zr-Ti) composite oxide thin film. It may be configured to form by depositing in a (sol-gel) manner. The forming of the metal thin film for increasing the reflectance of the driving reflector on the silicon nitride film formed on the first surface may include depositing any one of gold, platinum, and aluminum in a lift-off manner. Can be configured. The forming of the holder on the first surface of the substrate may be configured to form a holder using Su-8 material or CAR44 material.

According to another aspect of the present invention, there is provided a method of manufacturing a driving reflector structure of a corner cube retroreflector, comprising: forming a silicon on insulator (SOI) layer on a first surface of a substrate; Forming a material and an upper electrode material in order, etching the lower electrode material, the piezoelectric material, and the upper electrode material to form a driving piezoelectric cantilever and a fixed piezoelectric cantilever; and on the SOI layer formed on the first surface. Forming a thin metal film to increase the reflectance of the driving reflector, and dry etching the second surface such that four rectangular driving reflectors are formed at predetermined intervals in a cross shape in a predetermined central region of the substrate. Forming a holder on the SOI layer, etching at a second surface of the dry etched central region to form a cavity, It may be configured to include the step of releasing the group driving mirror, the driving piezoelectric cantilever and fixing the piezoelectric cantilever. The etching of the dry etched central region to form a cavity to release the driving reflector, the driving piezoelectric cantilever and the fixed piezoelectric cantilever may be configured to wet-etch or dry etch the central region to form a cavity. Can be. The etching of the dry-etched central region to form a cavity to release the driving reflector, the driving piezoelectric cantilever, and the fixed piezoelectric cantilever may include forming a cavity by wet etching the central region to form a cavity. It may be configured to wet etch using. Meanwhile, in the forming of the cavity by etching the dry-etched center region to release the driving reflector, the driving piezoelectric cantilever, and the fixed piezoelectric cantilever, in the case of dry etching the center region to form a cavity, a DRIE method is used. It may be configured to dry etching. The forming of the SOI layer on the first surface of the substrate may be configured to form the SOI layer by a chemical-mechanical polishing (CMP) process. And sequentially forming the lower electrode material, the piezoelectric material and the upper electrode material on the formed SOI layer may be configured to sputter titanium / platinum or platinum to form the lower electrode material or the upper electrode material. The forming of the lower electrode material, the piezoelectric material, and the upper electrode material in order on the formed SOI layer may be performed by depositing a lead-zirconium-titanium composite oxide thin film in a sol-gel manner. The forming of the metal thin film for increasing the reflectance of the driving reflector on the SOI layer formed on the first surface may be configured to deposit one of gold, platinum, and aluminum in a lift-off manner. And forming a holder on the SOI layer may be configured to form a holder using Su-8 material or CAR44 material.

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

First, the corner cube type retro reflector according to the present invention will be described with reference to FIGS. 2 to 6.

2 is a perspective view of a corner cube type retro reflector according to an embodiment of the present invention.

Referring to FIG. 2, the corner cube retroreflector 200 includes a substrate 210, a driving reflector 220, a driving piezoelectric cantilever 230, a fixed piezoelectric cantilever 240, a fixed reflector 250, and a holder 260. It can be configured to include). Here, the corner cube type retroreflector 200 includes a lower driving reflector structure and an upper portion including a substrate 210, a driving reflector 220, a driving piezoelectric cantilever 230, a fixed piezoelectric cantilever 240, and a holder 260. By combining the fixed reflector 250 can form a total of four corner cube shape. 3A and 4 separately illustrate the lower driving reflector structure and the upper fixed reflector 250, respectively. Hereinafter, each configuration of the corner cube type retro reflector 200 will be described in detail with reference to FIGS. 2, 3A, and 4.

Referring to FIG. 3A, the lower driving reflector structure may be configured to include a substrate 210, a driving reflector 220, a driving piezoelectric cantilever 230, a fixed piezoelectric cantilever 240, and a holder 260.

First, the substrate 210 may be configured to form a rectangular cavity area in the center area. As the substrate 210, a silicon wafer substrate may be used, and an SOI substrate may be used. The cavity area is an area for forming the driving reflector 220, the driving piezoelectric cantilever 230, and the fixed piezoelectric cantilever 240.

Four square driving reflecting mirrors positioned at predetermined intervals in a cross shape in the cavity region.

Four driving reflectors 220 may be provided in the cavity area, and may be configured to be positioned at a predetermined interval of a cross shape. In addition, the driving reflectors 220 may be configured to be arranged at a predetermined interval in a cross shape. The driving reflector 220 is a reflector that is rotatable at an angle and is a reflector for controlling the direction of the reflected light. The driving reflector 220 constitutes one surface of three corner cube shapes formed on the corner cube retroreflector 200. The driving reflector 220 may be made of any one material of gold (Au), platinum (Pt), and aluminum (Al) to improve reflectance.

The driving piezoelectric cantilever 230 is a configuration for connecting each corner of the cavity area and the first edge of each driving reflector 220 adjacent to each corner. The driving piezoelectric cantilever 230 functions to rotate the driving reflector 220 at a predetermined angle by using mechanical energy generated according to the piezoelectric driving method. The driving piezoelectric cantilever 230 may include a piezoelectric material, an upper electrode, and a lower electrode for generating a piezoelectric driving force. Lead-zirconium-titanium composite oxide may be used as the piezoelectric material, and metal electrodes such as titanium / platinum or platinum may be used for the upper electrode and the lower electrode. On the other hand, by applying a separate power to the upper electrode of each driving piezoelectric cantilever 230, mechanical energy can be generated in each of the driving piezoelectric cantilever 230, respectively. Accordingly, each driving reflector 220 may be driven at different angles at the same time.

The fixed piezoelectric cantilever 240 is configured to connect the second and third edges of the driving reflector 220 to each other and adjacent portions of the substrate 210, respectively. The fixed piezoelectric cantilever 240 serves to prevent bending or deflection of the driving reflector 220 during rotation of the driving reflector 220. More detailed explanation is as follows. When the driving reflector 220 rotates, the second and third edges of the driving reflector 220 are physically fixed by the fixed piezoelectric cantilever 240. Thus, at the same time as the rotation of the driving reflector 220, the second and third corners serve as one rotation axis, whereby the driving reflector 220 can maintain a constant flatness even when rotating.

The conventional driving piezoelectric cantilever 130 of FIG. 1 is formed in a structure that is hardly separated from the driving reflector 120, and thus has a disadvantage in that flatness is deteriorated. In particular, since both driving piezoelectric cantilevers 130 transmit mechanical energy to only one corner of the driving reflector 120, flatness is very poor during rotation. However, in the present invention, the disadvantage that the flatness worsens when the driving reflector 220 rotates is compensated.

Next, referring to FIG. 4, the fixed reflector 250 may be formed in a direction perpendicular to one surface of the substrate 210 at a predetermined interval of the cross shape and may include a predetermined protrusion 251. . The fixed reflector 250 constitutes two of three sides of the corner cube shape formed in the corner cube retro reflector 200.

Referring again to FIGS. 2 and 3A, a holder 260 may be formed on the substrate 210 to be coupled to the protrusion 251 to fix the fixed reflector 250 to the substrate 210. At this time, the holder 260 serves to ensure that each corner cube shape formed by the driving reflector 220 and the fixed reflector 250 is accurately aligned and fixed, thereby preventing the occurrence of the communication shadow area.

On the other hand, Figure 3b is a perspective view of a drive reflector structure according to another embodiment of the present invention.

Referring to FIG. 3B, the driving reflector structure may be configured to include a substrate 310, a driving reflector 320, a driving piezoelectric cantilever 330, a fixed piezoelectric cantilever 340, and a holder 360. Each configuration of the driving reflector structure of FIG. 3B is the same as that of each of the driving reflector structures of FIG. 3A, but the substrate 210 of FIG. 3A is removed from the cross-shaped predetermined intervals of the center region, and the substrate of FIG. 310 differs in that no cross-shaped predetermined spacing of the central region has been removed. When wet etching is performed in the manufacturing process of the driving reflector structure, a shape similar to the substrate 210 of FIG. 3A is formed. However, when dry etching, the same shape as the substrate 310 of FIG. 3B is formed.

Hereinafter, the driving of the driving reflector 220 will be described with reference to FIGS. 5 and 6.

5 is a plan view of a driving reflector according to an embodiment of the present invention, Figure 6 is a side cross-sectional view of the driving reflector according to an embodiment of the present invention. Referring to FIG. 5, the first edge of the driving reflector 220 is connected through the driving piezoelectric cantilever 230 and the first hinge 231. The second edge and the third edge of the driving reflector 220 are connected to each of the fixed piezoelectric cantilever 240 through the second hinge 241 and the third hinge 242. The hinges 231, 241, and 242 help the drive reflector 220 to rotate flexibly. A meander type hinge or a straight type hinge may be used.

Hereinafter, the manufacturing method of the corner cube type retroreflector 200 is demonstrated. The corner cube retroreflector 200, as described in the background art, uses a drive microstructure and a fixed reflector as it uses a bulk micro-machininig rather than a surface micro-machininig. 250 may be configured to be manufactured separately. In addition, the separately manufactured driving reflector structure and the fixed reflector 250 are configured to be coupled or assembled. Herein, various embodiments of a method of manufacturing a drive reflector structure having a characteristic structure according to the present invention will be described with reference to the drawings.

7A to 7I are flowcharts illustrating a method of manufacturing a driving reflector structure of a corner cube retroreflector according to an embodiment of the present invention.

First, referring to FIG. 7A, a silicon nitride film 702 is formed on the first and second surfaces of the substrate 701. The substrate 701 may be formed of a silicon substrate. The silicon nitride film formed on the first surface is formed to form the driving reflector 220, the driving piezoelectric cantilever 230, the fixed piezoelectric cantilever 240, and the hinges 231, 241, and 242. It can be configured to form by depositing a low stress nitride layer using (LPCVD).

Next, according to FIG. 7B, the lower electrode material 703, the piezoelectric material 704, and the upper electrode material 705 are sequentially formed on the silicon nitride film 702 formed on the first surface. In this case, the lower electrode material 703 and the upper electrode material 705 are deposited by sputtering, and metal materials such as titanium / platinum and platinum are used. The piezoelectric material 704 may be deposited in a sol-gel manner, and may be configured to deposit a lead-zirconium-titanium composite oxide thin film.

Next, referring to FIGS. 7C and 7D, the lower electrode material 703, the piezoelectric material 704, and the upper electrode material 705 are etched to form a driving piezoelectric cantilever and a fixed piezoelectric cantilever. In this case, the upper electrode material 705, the piezoelectric material 704, and the lower electrode material 703 may be dry etched in order to form shapes of the driving piezoelectric cantilever and the fixed piezoelectric cantilever. The upper electrode material 705 and the piezoelectric material 704 are dry etched using one mask, and the lower electrode material 703 is dry etched using a separate lower electrode mask.

Next, referring to FIG. 7E, a metal thin film for increasing the reflectance of the driving reflector is formed on the silicon nitride film 702 formed on the first surface of the substrate 701. The material of any one of gold, platinum, and aluminum is deposited by a lift-off method.

Referring to FIG. 7F, the second surface is dry-etched so that four square driving reflecting mirrors may be formed at predetermined intervals in a cross shape at a predetermined center region of the substrate 701.

Next, referring to FIG. 7G, a holder is formed on the first surface of the substrate 701. The holder uses Su-8 material or CAR44 material, which can produce a high aspect ratio.

Next, referring to FIG. 7H, the dry etched second surface is etched to form a cavity 708. In this case, the etching may use a wet etching method, and a KOH method or a TMAH method may be used.

Next, referring to FIG. 7I, the driving reflector 220, the driving piezoelectric cantilever 230, and the fixed piezoelectric cantilever 240 are released.

8A to 8I are flowcharts illustrating a method of manufacturing a driving reflector structure of a corner cube retro reflector according to another exemplary embodiment of the present invention.

First, referring to FIG. 8A, a silicon nitride film 802 is formed on the first and second surfaces of the substrate 801. The substrate 801 may be formed of a silicon substrate. The silicon nitride film formed on the first surface is formed to form a driving reflector 320, a driving piezoelectric cantilever 330, a fixed piezoelectric cantilever 340, and a hinge (not shown), and a low pressure chemical vapor deposition (LPCVD) method. It can be configured to be formed by depositing a low stress nitride layer using.

Next, according to FIG. 8B, the lower electrode material 803, the piezoelectric material 804, and the upper electrode material 805 are sequentially formed on the silicon nitride film 802 formed on the first surface. In this case, the lower electrode material 803 and the upper electrode material 805 are deposited by sputtering, and metal materials such as titanium / platinum and platinum are used. The piezoelectric material 804 may be deposited in a sol-gel manner, and may be configured to deposit a lead-zirconium-titanium composite oxide thin film.

8C and 8D, the lower electrode material 803, the piezoelectric material 804, and the upper electrode material 805 are etched to form a driving piezoelectric cantilever and a fixed piezoelectric cantilever. In this case, the upper electrode material 805, the piezoelectric material 804, and the lower electrode material 803 are dry-etched in this order to form shapes of the driving piezoelectric cantilever and the fixed piezoelectric cantilever. The upper electrode material 805 and the piezoelectric material 804 are dry etched using one mask, and the lower electrode material 803 is dry etched using a separate lower electrode mask.

Next, referring to FIG. 8E, a metal thin film for increasing the reflectance of the driving reflector is formed on the silicon nitride film 802 formed on the first surface of the substrate 801. The material of any one of gold, platinum, and aluminum is deposited by a lift-off method.

Referring to FIG. 8F, the second surface is dry-etched so that four rectangular driving reflecting mirrors may be formed at predetermined intervals in a cross shape in a predetermined center region of the substrate 801. In this case, the predetermined interval of the cross shape may be left as it is without etching.

Next, referring to FIG. 8G, a holder is formed on the first surface of the substrate 801. The holder uses Su-8 material or CAR44 material, which can produce a high aspect ratio.

Next, referring to FIG. 8H, a cavity 808 is formed by etching the dry etched second surface. In this case, the etching may use a dry etching method and the DRIE method may be used.

Next, referring to FIG. 8I, the driving reflector 320, the driving piezoelectric cantilever 330, and the fixed piezoelectric cantilever 340 are released.

9A-9I are a process diagram for a method of manufacturing a drive reflector structure of a corner cube type retroreflector according to another embodiment of the present invention.

Referring to FIG. 9A, an SOI layer is formed on the first surface of the substrate 901. The SOI layer allows for the formation of a silicon film 901 on the silicon oxide film 902. In this case, the upper silicon film 901 has a thin thickness to form the driving reflector 220, the driving piezoelectric cantilever 230, the fixed piezoelectric cantilever 240, and the hinges 231, 241, and 242. A chemical mechanical polishing process can be used for this.

Next, referring to FIG. 9B, the lower electrode material 903, the piezoelectric material 904, and the upper electrode material 905 are sequentially formed on the SOI layer. Here, the lower electrode material 903 and the upper electrode material 905 are deposited by sputtering, and metal materials such as titanium / platinum and platinum may be used. The piezoelectric material 904 may be formed by depositing a lead-zirconium-titanium composite oxide thin film in a sol-gel manner.

Next, referring to FIG. 9C, the lower electrode material 903, the piezoelectric material 904, and the upper electrode material 905 are etched to form a driving piezoelectric cantilever and a fixed piezoelectric cantilever. In this case, the upper electrode material 905, the piezoelectric material 904, and the lower electrode material 903 are sequentially dry-etched to form shapes of the driving piezoelectric cantilever and the fixed piezoelectric cantilever. The upper electrode material 905 and the piezoelectric material 904 are dry etched using one mask, and the lower electrode material 903 is dry etched using a separate lower electrode mask.

Next, referring to FIG. 9E, a metal thin film for increasing the reflectance of the driving reflector is formed on the SOI layer formed on the first surface. The material of any one of gold, platinum, and aluminum is deposited by a lift-off method.

Referring to FIG. 9F, the second surface is dry-etched so that four rectangular drive reflecting mirrors 220 may be formed at predetermined intervals in a cross shape at a predetermined center region of the substrate 901.

Next, referring to FIG. 9G, a holder is formed on the SOI layer. The holder uses Su-8 material or CAR44 material, which can produce a high aspect ratio.

Next, referring to FIG. 9H, a cavity 908 is formed by etching from the dry-etched second surface. In this case, the etching may use a wet etching method, and a KOH method or a TMAH method may be used.

Next, referring to FIG. 9I, the driving reflector 220, the driving piezoelectric cantilever 230, and the fixed piezoelectric cantilever 240 are released.

10A to 10I are flowcharts illustrating a method of manufacturing a driving reflector structure of a corner cube type retro reflector according to another embodiment of the present invention.

Referring to FIG. 10A, an SOI layer is formed on the first surface of the substrate 1001. The SOI layer allows to form the silicon film 1001 on the silicon oxide film 1002. In this case, the upper silicon film 1001 has a thin thickness to form the driving reflector 220, the driving piezoelectric cantilever 230, the fixed piezoelectric cantilever 240, and the hinges 231, 241, and 242. A chemical mechanical polishing process can be used for this.

Next, referring to FIG. 10B, the lower electrode material 1003, the piezoelectric material 1004, and the upper electrode material 1005 are sequentially formed on the SOI layer. Here, the lower electrode material 1003 and the upper electrode material 1005 are deposited by sputtering, and metal materials such as titanium / platinum and platinum may be used. The piezoelectric material 1004 may be formed by depositing a lead-zirconium-titanium composite oxide thin film in a sol-gel manner.

Next, referring to FIG. 10C, the lower electrode material 1003, the piezoelectric material 1004, and the upper electrode material 1005 are etched to form a driving piezoelectric cantilever and a fixed piezoelectric cantilever. In this case, the upper electrode material 1005, the piezoelectric material 1004, and the lower electrode material 1003 are sequentially dry-etched to form shapes of the driving piezoelectric cantilever and the fixed piezoelectric cantilever. The upper electrode material 1005 and the piezoelectric material 1004 are dry etched using one mask, and the lower electrode material 1003 is dry etched using a separate lower electrode mask.

Next, referring to FIG. 10E, a metal thin film for increasing the reflectance of the driving reflector is formed on the SOI layer formed on the first surface. The material of any one of gold, platinum, and aluminum is deposited by a lift-off method.

Referring to FIG. 10F, the second surface is dry-etched so that four rectangular drive reflecting mirrors 220 may be formed at predetermined intervals in a cross shape at a predetermined center region of the substrate 1001. In this case, the predetermined interval of the cross shape may be left as it is without etching.

Next, referring to FIG. 10G, a holder is formed on the SOI layer. The holder uses Su-8 material or CAR44 material, which can produce a high aspect ratio.

Next, referring to FIG. 10H, a cavity 1008 is formed by etching from the dry etched second surface. In this case, the etching may use a dry etching method and the DRIE method may be used.

Next, referring to FIG. 10I, the driving reflector 220, the driving piezoelectric cantilever 230, and the fixed piezoelectric cantilever 240 are released.

Although described with reference to the embodiments above, those skilled in the art will understand that the present invention can be variously modified and changed without departing from the spirit and scope of the invention as set forth in the claims below. Could be.

1 is a perspective view of a driving reflector structure of a corner cube retroreflector according to the prior art.

2 is a perspective view of a corner cube type retro reflector according to an embodiment of the present invention.

3A is a perspective view of a drive reflector structure in accordance with one embodiment of the present invention.

3B is a perspective view of a drive reflector structure according to another embodiment of the present invention.

4 is a perspective view of a fixed reflector according to an embodiment of the present invention.

5 is a plan view of a driving reflector according to an embodiment of the present invention.

6 is a side cross-sectional view of a driving reflector according to an embodiment of the present invention.

7A to 7I are flowcharts illustrating a method of manufacturing a driving reflector structure of a corner cube retroreflector according to an embodiment of the present invention.

8A to 8I are flowcharts illustrating a method of manufacturing a driving reflector structure of a corner cube retro reflector according to another exemplary embodiment of the present invention.

9A to 9I are flowcharts illustrating a method of manufacturing a drive reflector structure of a corner cube retroreflector according to another embodiment of the present invention.

10A to 10I are flowcharts illustrating a method of manufacturing a driving reflector structure of a corner cube type retro reflector according to another embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

110: substrate 120: driving reflector

130: driving piezoelectric cantilever 210: substrate

220: driving reflector 230: driving piezoelectric cantilever

231 hinge 240: fixed piezoelectric cantilever

241 hinge 310: substrate

320: driving reflector 330: driving piezoelectric cantilever

340: fixed piezoelectric cantilever 410: fixed reflector

420: protrusion

Claims (22)

A substrate having a rectangular cavity area formed in a central area thereof; Four rectangular drive reflecting mirrors positioned at predetermined intervals in a cross shape in the cavity area; A driving piezoelectric cantilever for connecting each corner of the cavity region and a first edge of each driving reflector adjacent to each corner; A fixed piezoelectric cantilever for connecting the second and third edges of the driving reflector to each other and adjacent portions of the substrate, respectively; A fixed reflector formed in a direction perpendicular to one surface of the substrate on a predetermined interval of the cross shape and having a predetermined protrusion; And a holder formed on the substrate in combination with the protrusion to fix the fixed reflector to the substrate. The method of claim 1, The driving piezoelectric cantilever is connected to the first edge of the driving reflector through a first hinge, And the fixed piezoelectric cantilever is connected to the second and third edges of the driving reflector through a second hinge and a third hinge, respectively. The method of claim 2, And said first hinge, second hinge and third hinge are meander type hinges or straight type hinges. The method of claim 3, And the driving piezoelectric cantilever is driven individually, respectively. Forming a silicon nitride film on the first and second surfaces of the substrate; Sequentially forming a lower electrode material, a piezoelectric material, and an upper electrode material on the silicon nitride film formed on the first surface; Etching the lower electrode material, the piezoelectric material and the upper electrode material to form a driving piezoelectric cantilever and a fixed piezoelectric cantilever; Forming a metal thin film on the silicon nitride film formed on the first surface to increase the reflectance of the driving reflector; Dry etching the second surface such that four quadrangular driving reflecting mirrors are formed at predetermined intervals in a cross shape in a predetermined center region of the substrate; Forming a holder on the first surface of the substrate; And etching the second surface of the dry etched central region to form a cavity to release the drive reflector, the drive piezoelectric cantilever, and the fixed piezoelectric cantilever. The method of claim 5, Etching the dry-etched central region to form a cavity to release the driving reflector, the driving piezoelectric cantilever and the fixed piezoelectric cantilever, And wet-etching or dry-etching the central region to form a cavity. The method of claim 6, Etching the dry-etched central region to form a cavity to release the driving reflector, the driving piezoelectric cantilever and the fixed piezoelectric cantilever, In the case of forming a cavity by wet etching the central region, wet etching is performed using the KOH method or the TMAH method. The method of claim 7, wherein Etching the dry-etched central region to form a cavity to release the driving reflector, the driving piezoelectric cantilever and the fixed piezoelectric cantilever, In the case of forming a cavity by dry etching the central region, dry etching using a DRIE method, the method of manufacturing a drive reflector structure of a corner cube retro-reflector. The method of claim 8, Forming a silicon nitride film on the first and second surfaces of the substrate, A low stress nitride film is formed by a low pressure chemical vapor deposition method. 10. The method of claim 9, In the step of forming a lower electrode material, a piezoelectric material, an upper electrode material on the silicon nitride film formed on the first surface in order, 30. A method of manufacturing a drive reflector structure of a corner cube retroreflector characterized by sputtering titanium / platinum or platinum to form a lower electrode material or an upper electrode material. The method of claim 10, In the step of forming a lower electrode material, a piezoelectric material, an upper electrode material on the silicon nitride film formed on the first surface in order, A method of manufacturing a driving reflector structure for a corner cube retroreflector, characterized by depositing a lead-zirconium-titanium composite oxide thin film by a sol-gel method. The method of claim 11, Forming a metal thin film for increasing the reflectance of the driving reflector on the silicon nitride film formed on the first surface, A method of manufacturing a driving reflector structure of a corner cube type retroreflector, comprising depositing any one of gold, platinum, and aluminum in a lift-off manner. The method of claim 12, Forming a holder on the first surface of the substrate, A method of manufacturing a drive reflector structure for a corner cube retroreflector, characterized by forming a holder using Su-8 material or CAR44 material. Forming an SOI layer on the first side of the substrate; Sequentially forming a lower electrode material, a piezoelectric material, and an upper electrode material on the formed SOI layer; Etching the lower electrode material, the piezoelectric material and the upper electrode material to form a driving piezoelectric cantilever and a fixed piezoelectric cantilever; Forming a metal thin film on the SOI layer formed on the first surface to increase the reflectance of the driving reflector; Dry etching the second surface of the substrate such that four rectangular drive reflecting mirrors are formed at predetermined intervals in a cross shape in a predetermined center region of the substrate; Forming a holder on the SOI layer; Etching on the second surface of the dry etched central region to form a cavity; and And releasing said drive reflector, said drive piezoelectric cantilever and said fixed piezoelectric cantilever. The method of claim 14, Etching the dry-etched central region to form a cavity to release the driving reflector, the driving piezoelectric cantilever and the fixed piezoelectric cantilever, And wet-etching or dry-etching the central region to form a cavity. The method of claim 15, Etching the dry-etched central region to form a cavity to release the driving reflector, the driving piezoelectric cantilever and the fixed piezoelectric cantilever, In the case of forming a cavity by wet etching the central region, wet etching is performed using the KOH method or the TMAH method. The method of claim 16, Etching the dry-etched central region to form a cavity to release the driving reflector, the driving piezoelectric cantilever and the fixed piezoelectric cantilever, In the case of forming a cavity by dry etching the central region, dry etching is performed using a DRIE method. The method of claim 17, Forming an SOI layer on the first side of the substrate, A method for producing a drive reflector structure for a corner cube retroreflector, characterized by forming a SOI layer by a chemical mechanical polishing process. The method of claim 18, Forming a lower electrode material, a piezoelectric material and an upper electrode material in order on the formed SOI layer, 30. A method of manufacturing a drive reflector structure of a corner cube retroreflector characterized by sputtering titanium / platinum or platinum to form a lower electrode material or an upper electrode material. The method of claim 19, Forming a lower electrode material, a piezoelectric material and an upper electrode material in order on the formed SOI layer, A method of manufacturing a driving reflector structure for a corner cube retroreflector, characterized by depositing a lead-zirconium-titanium composite oxide thin film by a sol-gel method. 21. The method of claim 20, Forming a metal thin film to increase the reflectance of the driving reflector on the SOI layer formed on the first surface, A method of manufacturing a driving reflector structure of a corner cube type retroreflector, comprising depositing any one of gold, platinum, and aluminum in a lift-off manner. The method of claim 21, Forming a holder on the SOI layer, A method of manufacturing a drive reflector structure for a corner cube retroreflector, characterized by forming a holder using Su-8 material or CAR44 material.

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