KR100459410B1 - Light modulator and method for producing of light modulator - Google Patents

Abstract

The present invention is a conventional optical modulator device, the drive plate having a light inlet formed through the substrate, and both ends are fixed to the drive plate so as to span the upper end of the light inlet, the light incident through the light inlet A fixed ribbon composed of a reflecting film to reflect, and both ends are fixed to the drive plate to cover the upper end of the light inlet, alternately installed at regular intervals with the fixed ribbon, a conductive film and the light incident through the light inlet A driving ribbon comprising a reflective film for reflecting light, a driving ribbon electrode pad connected to the driving ribbon so as to apply electricity to the conductive film, an electrode plate having a predetermined gap between the fixed ribbon and the upper end of the driving ribbon; And a ground plate having an electrode for applying electricity to the electrode plate, and maintaining a gap between the driving plate and the ground plate. By providing an optical modulator device, characterized in that configured to include a spacer is installed, the drive ribbon is made on a substrate and the same plane is structurally stable. Therefore, it is possible to increase the yield at the time of manufacture, it is easy to mass production can lower the manufacturing cost. In addition, the gap between the ground plate and the driving ribbon can be adjusted to a desired height using a spacer.

Description

LIGHT MODULATOR AND METHOD FOR PRODUCING OF LIGHT MODULATOR}

The present invention relates to an optical modulator element, and more particularly, to an optical modulator element for laser display.

Recently, the GLV (Grating Light Valve) method, which is a display method using a laser beam, is a method of composing an image using a diffraction phenomenon of a beam, and has excellent characteristics in various aspects such as contrast and color. The optical modulator device used in the GLV method is manufactured by using surface micro-machining technology. Six microribbons having a micro bridge shape formed on a silicon substrate are formed into one pixel. It is composed.

1 to 5 show the structure of a conventional optical modulator element, FIG. 1 is a schematic view of a display system using the optical modulator element, FIG. 2 is a perspective view of the optical modulator element of FIG. 1, FIG. 4 is a cross sectional view of the optical modulator element in which the display of FIG. 1 is in a dark state, and FIG. 5 is a cross-sectional view of an optical modulator element in which the display of FIG. 1 is in a bright state.

As shown in FIG. 1, a display system using an optical modulator element includes a light source 31 for irradiating light, such as a laser diode, and a prism 31 for transmitting light from the light source 31 to the optical modulator 100. And an optical modulator device 100 that receives and reflects the light reflected from the prism 31, and two lenses 33 and 34 that are incident on the screen 35 by refracting the light reflected by the optical modulator device 100. It is composed of

In the structure of the optical modulator device 100 using the conventional GLV method, as shown in FIG. 2, an insulating layer 112 is formed of a dielectric film such as Si 3 N 4 or SiO 2 on the silicon substrate 111, and the insulation is performed. A lower electrode 113 made of a high temperature metal film (refractory metal film) such as tungsten (W) is formed on the layer 112, and a ribbon 120 in the form of a micro bridge is formed on the gap with the lower electrode 113. The substrate 111 is formed on the substrate 111. The upper surface of the ribbon 120 is formed with a metal thin film having high reflection efficiency, such as aluminum that can reflect incident light and act as an electrode. The ribbon 120 is fixed to the end portion 121 formed at both ends to be fixed to the substrate 111, and bent upward from the fixing portion 121 is a constant distance from the substrate 111 to the ribbon 120 It is composed of a post portion 122 spaced apart from the reflection portion 123 formed to be bent in parallel to the substrate 111 in the post portion 122.

One pixel is composed of six ribbons 120, three of which are driving ribbons 120A, and three of which are fixed ribbons 120B. The driving ribbon 120A and the fixed ribbon 120B are alternately installed. The fixed ribbon 120B is electrically connected to the lower electrode 113 so that a potential difference does not occur with the lower electrode 113 even when a voltage is applied. The driving ribbon 120A moves in the vertical direction by the electrostatic force.

4 is a cross-sectional view of the optical modulator element in which the display of FIG. 1 is in a dark state, and FIG. 5 is a cross-sectional view of the optical modulator element in which the display of FIG.

If no voltage is applied, all six ribbons 120 are aligned at the same position as shown in FIG. 4, and the reflected light 126 is all reflected in the direction in which the incident light 125 is incident, and re-entered into the light source 31. The screen 35 is in a dark state in which no image appears.

When the voltage is applied, the reflective portion 123 of the driving ribbon 120A is struck downward as shown in FIG. 5, while the reflected light 127 of the driving ribbon 120A passes between the fixed ribbons 120B. Diffraction occurs and exits with a diffraction angle, and the reflected light 127 is projected onto the screen 35 via the lenses 33 and 34. The diffraction angle becomes larger as the pixel size becomes smaller. Considering the display system, the larger the diffraction angle, the better, because the larger the diffraction angle, the better the size of the system.

However, the conventional optical modulator device 100 has a problem in that the stress is concentrated on the post portion 122 of the ribbon 120 and structurally weak, and the ribbon 120 has a large aspect ratio bridge. Since the ribbon 120 has a high probability of bending or breaking due to stress in a shape, it is difficult to secure the manufacturing process and reliability of the device. In addition, when a voltage higher than a reference voltage is applied, there is a problem that fusion may occur that the ribbon 120 does not stick to the lower electrode 113.

The present invention has been made to solve the above problems, by having a structurally stable ribbon, it is possible to increase the yield at the time of manufacture, to reduce the manufacturing cost by easy mass production, fusion between the drive ribbon and the lower electrode It is an object of the present invention to provide an optical modulator device that prevents the loss.

1 to 5 show a configuration of a conventional optical modulator element,

1 is a schematic diagram of a display system using an optical modulator element

FIG. 2 is a perspective view of the optical modulator element of FIG. 1

3 is a longitudinal cross-sectional view of the optical modulator element of FIG.

4 is a cross-sectional view of an optical modulator element in which the display of FIG. 1 is in a dark state;

FIG. 5 is a cross sectional view of the optical modulator element in which the display of FIG. 1 is in a bright state; FIG.

6 to 10 are views showing the structure of the first embodiment of the present invention.

6 is a cross sectional view of an optical modulator element;

7 is a plan view of the driving plate of FIG.

8 is a cross-sectional view of the drive plate of FIG.

Figure 9 is a bottom view of the ground plate of Figure 6

10 is a cross sectional view of the ground plate of FIG.

11 to 13 show the structure of a second embodiment of the present invention.

11 is a cross-sectional view of an optical modulator element

Figure 12 is a bottom view of the ground plate of Figure 11

Figure 13 is a cross sectional view of the ground plate of Figure 12

** Description of the symbols for the main parts of the drawings **

210: driving plate 211: driving plate substrate

213: first insulating film 216: fixed ribbon

217: driving ribbon 218: driving ribbon electrode pad

227: reflecting film, conductive film 221: light inlet

226: fixed ribbon ground pad 250: ground plate

251: ground plate substrate, electrode plate 252: electrode

253: ground plane bottom insulating film 254 spacer

260: insulating adhesive 274: anti-stick protrusions

The present invention provides a drive plate having a light inlet formed through the substrate to achieve the above object; A fixed ribbon fixed at both ends to the driving plate so as to extend over the light inlet, and having a reflective film to reflect light incident through the light inlet; Both ends are fixed to the driving plate so as to span the upper end of the light inlet, alternately installed at regular intervals from the fixed ribbon, and a drive ribbon including a conductive film and a reflecting film reflecting light incident through the light inlet. and; A driving ribbon electrode pad connected to the driving ribbon so as to apply electricity to the conductive film; An electrode plate provided at an upper end of the fixed ribbon and the driving ribbon with a predetermined gap, and a ground plate having an electrode for applying electricity to the electrode plate; A spacer provided to maintain a gap between the driving plate and the ground plate; It provides an optical modulator device comprising a.

In addition, the ground plate is preferably fixed to the drive plate with an insulating adhesive.

In addition, it is preferable that the driving ribbon and the ground plate further comprises a fixing preventing protrusion formed by protruding a plurality of the ground plate in a portion which is folded with the driving ribbon in order to prevent the contact.

On the other hand, the present invention comprises a grounding plate including the electrode plate step; A driving plate having a driving plate including a driving ribbon and a fixed ribbon formed of a conductive reflective film, and a light introduction port formed to introduce light into the reflective film; Securing the ground plate to the drive plate with an insulating adhesive; It can also be implemented as a method for producing an optical modulator device including.

The driving plate preparation step may include: a first insulating film deposition step of depositing a thin film of the first insulating film on the driving plate substrate; A ground pad ground line forming step of depositing and patterning a metal thin film on the first insulating layer to form a ground pad and a ground line connected to the ground pad; A second insulating film deposition step of depositing a thin film of a second insulating film on the ground line; Forming a via hole by etching a portion of the second insulating layer to expose the ground line; Depositing a metal thin film to form a reflective film and a conductive film on the second insulating film; Patterning the metal thin film to form a driving ribbon and a fixed ribbon formed to cross each other, a fixed ribbon ground pad extending to the fixed ribbon, and a driving ribbon electrode pad extending to the driving ribbon; Forming a lower surface insulating film on the lower surface of the substrate; A light inlet forming step of forming a light inlet so that the first insulating film is exposed by anisotropically etching the substrate by patterning the bottom insulating film and removing a portion thereof; A ribbon forming step of forming a fixed ribbon and a driving ribbon by etching portions of the first insulating layer on the light inlet, other than where the fixed ribbon and the driving ribbon are deposited; It is preferable to comprise.

In addition, the step of providing a ground plate comprises the steps of: providing a doped silicon substrate as a ground plate substrate; Depositing an insulating film on the bottom surface of the ground plate substrate to form a ground plate bottom insulating film; A spacer forming step formed side by side in a bar shape on the bottom surface of the bottom surface insulating film; Forming an electrode by depositing a metal on an upper surface of the ground plate substrate to apply a ground signal to the ground plate substrate; It is preferable to comprise.

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

However, in describing the present invention, a detailed description of known functions or configurations will be omitted in order not to disturb the gist of the present invention.

In addition, the same reference numerals are given to the same and the same components as those described above, and detailed description thereof will be omitted.

6 to 10 show the structure of the first embodiment of the present invention, FIG. 6 is a cross sectional view of an optical modulator element, FIG. 7 is a plan view of the drive plate of FIG. 6, and FIG. 8 is a cross sectional view of the drive plate of FIG. 9 is a bottom view of the ground plate of FIG. 6, and FIG. 10 is a cross sectional view of the ground plate of FIG.

The optical modulator element 200 according to the first embodiment of the present invention includes a driving plate 210 having a light introduction hole 221 and a ground plate 250 provided with a predetermined gap on the driving plate 210. .

The driving plate 210 is etched in a triangular shape on the substrate 211 to penetrate the substrate 211, the first insulating layer 213 formed on the upper surface of the substrate, and the substrate A lower insulating film 212 formed on a lower surface, a ground wire 214 formed around the light inlet 221 on the first insulating film 213, and a ground pad 219 formed to ground the ground wire 214. And a second insulating film 220 formed on the ground line 214, and a reflective film 227 formed on the first insulating film 213 and the second insulating film 213.

The reflective film 227 and the first insulating film 213 are etched on the upper surface of the light inlet 221 so that the thin fixed ribbon 216 and the driving ribbon 217 are alternately formed. Both ends of the fixed ribbon 216 and the driving ribbon 217 are fixed to the first insulating layer 213 across the light inlet 221. In addition, a fixed ribbon ground pad 226 connecting the ground line 214 and the fixed ribbon 216 to ground the fixed ribbon 216 to the ground pad 219 is formed, the driving ribbon 216 The driving ribbon electrode pad 218 connected to the driving ribbon 216 is formed on the first insulating layer 213 to apply electricity to the first insulating layer 213. The driving ribbon electrode pad 218 and the fixed ribbon ground pad 226 are both formed by patterning the reflective film 227. In addition, in order to enable the fixed ribbon ground pad 226 and the ground line 214 to be electrically conductive, the via hole 215 is formed to partially expose the second insulating layer 213 to expose the ground line 214. Afterwards, the fixed ribbon ground pad 226 is formed on the via hole 215.

Preferably, the substrate 211 uses a silicon substrate, and the first insulating layer and the lower insulating layer 212 simultaneously perform the role of an insulating layer and the driving ribbon 217, thereby providing excellent insulation and mechanical elasticity. It is preferable to form a silicon nitride (SixNy) thin film by a thin film deposition method such as low pressure chemical vapor deposition (LPCVD). In addition, the ground pad 219 and the ground wire 214 are deposited on a thin film such as sputtering a high-temperature refractory metal film such as tungsten (W) or tungsten silicide (WSi) to be stable in a high temperature process. It is preferable to form by depositing by patterning and patterning. In addition, the second insulating layer is preferably formed on the ground line 214 by depositing SiO 2 or Si 3 N 4 by chemical vapor deposition (CVD) or the like. In addition, the reflective film 227 is formed of aluminum (Al) or gold (Au) thin film by the sputtering method and patterned by the fixed ribbon 216, the driving ribbon 217 and the fixed ribbon pad 226, and It is preferable to form the drive ribbon pad 218. Since the reflective film 227 is conductive, it functions as a conductive film.

The ground plate 250 may include a ground plate substrate 251, an electrode 252 formed on an upper surface of the substrate 251, a ground plate lower surface insulating layer 253 formed on a lower surface of the substrate 251, and the lower surface thereof. The spacer 254 is formed on the lower surface of the insulating film 253 and is formed in parallel with each other in a bar shape.

The ground plate substrate 251 allows the substrate itself to be used as an electrode plate using a doped silicon substrate. In addition, the lower insulating film 253 is preferably formed on the ground plate substrate 252 by a low pressure chemical vapor deposition method. In addition, the electrode 252 is preferably formed by depositing Au or the like by a sputtering method in order to apply a ground signal to the ground plate substrate 251.

As shown in FIG. 6, the ground plate 250 is fixed by an insulating adhesive 260 such that the spacer 254 is positioned on the driving plate 210 with the light inlet 221 interposed therebetween. The ground plate 250 and the ground pad 219 are electrically connected to each other. The insulating adhesive 260 may use epoxy.

Hereinafter, the manufacturing method of the first embodiment of the present invention will be described.

The manufacturing method of the driving plate 210 is as follows.

A silicon nitride (SixNy) thin film is deposited on the silicon substrate 211 by a thin film deposition method such as a low pressure chemical vapor deposition method to form the first insulating layer 213 and thereon tungsten (W). ) Or a high temperature metal thin film (refractory metal film) such as tungsten silicide (WSi) is deposited by a thin film deposition method such as sputtering method and then patterned to form the ground pad 219 and the ground line 214. . Next, an insulating film such as SiO 2 or Si 3 N 4 is deposited by chemical vapor deposition, or the like, to be patterned to form a second insulating film 220 on the ground line 214. The via hole 215 is patterned to separate the fixed ribbon ground pad 226 and the driving ribbon electrode pad 218. An aluminum (Al) or gold (Au) thin film, which can be used as a reflective film, is formed on the sputtering method and patterned to form the fixed ribbon 216, the fixed ribbon ground pad 226, the driving ribbon 217, and the driving pattern. The ribbon electrode pad 218 is formed. Next, a thin film of silicon nitride is fixed on the lower surface of the substrate 211 to form the lower insulating film 212, and then partially removed by patterning the silicon nitride. The silicon substrate is then anisotropically etched with a KOH solution (potassium hydroxide-water) to form a silicon substrate. A portion of the light guide hole 221 is formed to expose the first insulating layer 213. Finally, the exposed portions of the first insulating layer 213 are dry-etched by using a hard mask on the fixed ribbon 216 and the reflective film 227 of the driving ribbon 217 on the front surface by using a hard mask. The fixed ribbon 216 and the driving ribbon 217 are formed by removing the penetrating ribbon.

The manufacturing method of the ground plate 250 is as follows.

The ground plate substrate 251 uses a doped silicon substrate. A silicon nitride thin film is deposited on the lower surface of the ground plate substrate 251 by a low pressure chemical vapor deposition method to form the ground plate lower insulating film 253. The spacer 254 is formed on a bottom surface of the bottom surface insulating layer 253. In order to apply a ground signal to the ground plate, Au and the like are deposited on the upper surface of the ground plate substrate by sputtering to form an electrode 252.

The operation of the first embodiment of the present invention will be described below. The operation of the display system is the same as the above-described prior art, and therefore the operation of the optical modulator element will be described.

The fixed ribbon 216 is electrically connected to the ground line 214 through the via hole 215, and the ground line 214 is grounded to the ground plate 250 through the ground pad 219. There is no potential difference between the fixed ribbon 216 and the ground plate 250. However, since the driving ribbon 216 is electrically open to the ground plate 250, by applying electricity to the driving ribbon electrode pad 218, the driving plate 216 is attracted to the ground plate 250. Therefore, the degree of bending of the driving ribbon 217 may be adjusted according to the amount of electricity applied to the driving ribbon electrode pad 218.

Light incident from the light source 31 is incident through the light inlet 221 to be reflected and diffracted by the fixed ribbon 216 and the driving ribbon 217 on which the reflective film 227 is formed, and thus the screen ( 35).

As described above, the optical modulator element of the first embodiment of the present invention is structurally stable because the driving ribbon is coplanar with the substrate. Therefore, it is possible to increase the yield at the time of manufacture, it is easy to mass production can lower the manufacturing cost.

In addition, the gap between the ground plate and the driving ribbon can be adjusted to a desired height using a spacer.

11 to 13 show a structure of a second embodiment of the present invention, FIG. 11 is a cross sectional view of an optical modulator element, FIG. 12 is a bottom view of the ground plate of FIG. 11, and FIG. 13 is a cross sectional view of the ground plate of FIG. to be.

The structure of the optical modulator element of the second embodiment differs only in the structure of the ground plate 250, and is the same as that of the optical modulator element of the first embodiment of the other configuration. Therefore, hereinafter, the structure of the ground plate 250 will be described.

The ground plate 250 includes a ground plate substrate 251, an electrode 252 formed on an upper surface of the substrate 251, a ground plate lower surface insulating layer 273 formed on a lower surface of the substrate 251, and the lower surface thereof. A spacer 254 formed in a bar shape on the bottom surface of the insulating film 273 and facing each other in parallel, and an adhesion preventing protrusion 274 formed by partially etching the insulating film 273 between the spacers 254. It is configured by.

The ground plate substrate 251 allows the substrate itself to be used as an electrode plate using a doped silicon substrate. In addition, the lower insulating film 253 is preferably formed on the ground plate substrate 252 by a low pressure chemical vapor deposition method. In addition, the electrode 252 is preferably formed by depositing Au or the like by a sputtering method in order to apply a ground signal to the ground plate substrate 251. In addition, the adhesion preventing protrusion 274 is preferably formed by patterning the insulating film 253 by dry etching.

As described above, the optical modulator device according to the second embodiment of the present invention includes an anti-sticking protrusion, thereby preventing fusion caused when the driving ribbon is folded to the ground plate.

According to the embodiment of the present invention as described above it can be expected a variety of effects including the following matters. However, the present invention is not achieved by exerting all of the following effects.

First, the drive ribbon is structurally stable by being coplanar with the substrate. Therefore, it is possible to increase the yield at the time of manufacture, it is easy to mass production can lower the manufacturing cost.

In addition, the gap between the ground plate and the driving ribbon can be adjusted to a desired height using a spacer.

In addition, by providing the anti-stick protrusion, it is possible to prevent the fusion generated when the driving ribbon is folded to the ground plate.

Claims (12)

A driving plate having a light inlet formed through the substrate; A fixed ribbon fixed at both ends to the driving plate so as to extend over the light inlet, and having a reflective film to reflect light incident through the light inlet; Both ends are fixed to the driving plate so as to span the upper end of the light inlet, alternately installed at regular intervals from the fixed ribbon, and a drive ribbon including a conductive film and a reflecting film reflecting light incident through the light inlet. and; A driving ribbon electrode pad connected to the driving ribbon so as to apply electricity to the conductive film; An electrode plate provided at an upper end of the fixed ribbon and the driving ribbon with a predetermined gap, and a ground plate having an electrode for applying electricity to the electrode plate; A spacer provided to maintain a gap between the driving plate and the ground plate; Optical modulator device comprising a. The method of claim 1, And the ground plate is fixed to the drive plate with an insulating adhesive. The method of claim 2, The driving modulator and the ground plate is in contact with the ground plate in order to prevent the fixing further comprises a plurality of protruding prevention protrusions formed in the ground portion is folded with the driving ribbon optical modulator device. According to any one of claims 1 to 3, wherein the drive ribbon It consists of an insulating film composed of silicon nitride having elasticity, And the reflecting film and the conductive film are integrally formed of aluminum foil or gold foil on the insulating film. The method of claim 4, wherein The fixed ribbon is composed of an insulating film made of silicon nitride, the reflective film is an aluminum foil or gold foil formed on the insulating film, And a fixed ribbon ground pad formed by extending the reflective film of the fixed ribbon to connect the fixed ribbon to an electrode of the ground plate. The method of claim 5, wherein the anti-stick protrusions And forming a plurality of ribs by etching a portion of the insulating film after forming an insulating film on the ground plate. The method of claim 6, A ground wire connected to the ground pad to connect the fixed ribbon ground pad to an electrode of the ground plate; A ground pad having one end connected to the ground line and the other end electrically connected to an electrode of the ground plate; An optical modulator device characterized in that it further comprises. A ground plate assembling step including an electrode plate; A driving plate having a driving plate including a driving ribbon and a fixed ribbon formed of a conductive reflective film, and a light introduction port formed to introduce light into the reflective film; Securing the ground plate to the drive plate with an insulating adhesive; Optical modulator device production method characterized in that it comprises a. The method of claim 8, wherein the driving plate preparing step Depositing a first insulating film on the driving plate substrate; A ground pad ground line forming step of depositing and patterning a metal thin film on the first insulating layer to form a ground pad and a ground line connected to the ground pad; A second insulating film deposition step of depositing a thin film of a second insulating film on the ground line; Forming a via hole by etching a portion of the second insulating layer to expose the ground line; Depositing a metal thin film to form a reflective film and a conductive film on the second insulating film; Patterning the metal thin film to form a driving ribbon and a fixed ribbon formed to cross each other, a fixed ribbon ground pad extending to the fixed ribbon, and a driving ribbon electrode pad extending to the driving ribbon; Forming a lower surface insulating film on the lower surface of the substrate; A light inlet forming step of forming a light inlet so that the first insulating film is exposed by anisotropically etching the substrate by patterning the bottom insulating film and removing a portion thereof; A ribbon forming step of forming a fixed ribbon and a driving ribbon by etching portions of the first insulating layer on the light inlet, other than where the fixed ribbon and the driving ribbon are deposited; Optical modulator device production method characterized in that it comprises a. The method of claim 9, In the first insulating film deposition step, a low pressure chemical vapor deposition (LPCVD) method is performed on a silicon nitride (SixNy) thin film on the driving plate substrate. In the forming of the ground pad ground line, a high temperature metal thin film such as tungsten (W) or tungsten silicide (WSi) is deposited on the first insulating layer by sputtering and then patterned to form the ground pad and the ground line. , In the deposition of the second insulating film, an insulating film such as SiO 2 or Si 3 N 4 is deposited by chemical vapor deposition (CVD) and then patterned to form a second insulating film 220 on the ground line. The metal thin film deposition step is characterized in that the aluminum (Al) or gold (Au) thin film is deposited by a sputtering method, The lower surface insulating film forming step is characterized in that to deposit a thin film of silicon nitride, The light inlet forming step is characterized in that using the KOH solution as an etchant, The ribbon forming step may include removing the reflective portions of the fixed ribbon and the driving ribbon by dry etching the exposed portions of the first insulating layer using a hard mask. An optical modulator device production method characterized by the above-mentioned. The method of any one of claims 8 to 10, wherein the ground plate providing step Providing a doped silicon substrate as a ground plane substrate; Depositing an insulating film on the bottom surface of the ground plate substrate to form a ground plate bottom insulating film; A spacer forming step formed side by side in a bar shape on the bottom surface of the bottom surface insulating film; Forming an electrode by depositing a metal on an upper surface of the ground plate substrate to apply a ground signal to the ground plate substrate; Optical modulator device production method characterized in that it comprises a. The method of claim 11, The forming of the insulating layer on the bottom surface of the ground plate may include depositing a silicon nitride thin film by low pressure chemical vapor deposition (LPCVD). The electrode forming step of the optical modulator device production method characterized in that the deposition of Au on the upper surface of the ground plate substrate by a sputtering method.