KR100251107B1 - Thin film type light-path controlling device and its fabrication method - Google Patents

Abstract

PURPOSE: A thin film type light road controller and a method for manufacturing are provided to improve an optical efficiency of a light incident from a light source by forming an actuator having an upper electrode consisting of multiple layers. CONSTITUTION: An active matrix(100) comprises the first metal layer(125) formed on a transistor(103) and having a drain pad, the first protective layer(130) formed on the first metal layer(125) and the transistor(103), the second metal layer(135) formed on the first protective layer(130), the second protective layer(140) formed on the second metal layer(135), and an etching preventing layer(145) formed on the second protective layer(140). An actuator(200) comprises a supporting layer(155) contacted with a drain pad of the first metal layer(125) and formed in parallel with the etching preventing layer(145) with an air gap(190), a lower electrode(160) formed on the supporting layer(155), a strain layer(165) formed on the lower electrode(160), and a via contact(180) formed inside of a via hole(175). The upper electrode(170) involves the first upper electrode layer(170a), the second upper electrode layer(170b) formed on the first upper electrode layer, and the third upper electrode layer(170c) formed on the second upper electrode layer. A stripe(185) is formed in a side of the upper electrode(170) to operate the upper electrode(170) uniformly and prevent an incident light from reflecting diffusely.

Description

Thin film type optical path control device and its manufacturing method

The present invention relates to an AMA (Actuated Mirror Array), which is a thin film type optical path control device, and a method for manufacturing the same. More specifically, an upper electrode including a plurality of layers, such as aluminum having excellent reflectivity, platinum having excellent etching resistance, and tantalum having excellent electrical conductivity. It is to provide a thin film type optical path control apparatus and a method of manufacturing the same that can improve the light efficiency of the light incident from the light source by forming an actuator having a.

An optical path adjusting device or an optical modulator capable of adjusting the light flux may be variously applied to optical communication, image processing, and information display apparatus. In general, such devices are classified into two types according to their optical properties. One type is a direct view type image display device, such as a CRT (Cathode Ray Tube), and the other type is a projection type image display device, a liquid crystal display (LCD), a deformable mirror device (DMD), or This includes AMA. Although the CRT apparatus has excellent image quality, the weight and volume of the CRT apparatus increases, leading to an increase in manufacturing cost. On the other hand, the liquid crystal display (LCD) has a simple optical structure and can be formed thin so that the weight can be reduced and the volume can be reduced. However, the liquid crystal display device is inferior in efficiency to have a light efficiency of 1 to 2% due to polarization of light, has a disadvantage in that the response speed of the liquid crystal material is slow and the inside thereof is easily overheated.

Thus, in order to solve the above problems, an image display device such as AMA or DMD has been developed. Currently, AMA can achieve a light efficiency of 10% or more, compared to a DMD having a light efficiency of about 5%. The AMA is a device that can adjust the speed of light so that each of the mirrors installed therein reflects the light flowing from the light source at a predetermined angle, and the reflected light passes through a slit to form an image on the screen. Therefore, the structure and operation principle thereof are simple, and high light efficiency can be obtained compared to a liquid crystal display device or a DMD. In addition, it is possible to obtain a bright and clear image by improving contrast, and not only is not affected by the polarity of the incident light, but also does not affect the polarity of the reflected light. The mirrors embedded in the AMA are arranged to correspond to the slits, respectively, and the upper mirror is inclined by an electric field generated inside the actuator. Therefore, the light incident from the light source is adjusted at a predetermined angle to form an image on the screen. In general, each actuator generates a deformation in accordance with the electric field generated by the applied electric image signal and the bias signal. When the actuator causes deformation, each of the mirrors mounted on top of the actuator is tilted. Accordingly, the inclined mirrors can reflect light incident from the light source at a predetermined angle. Piezoelectric materials such as PZT (Pb (Zr, Ti) O ₃ ) or PLZT ((Pb, La) (Zr, Ti) O ₃ ) are used as constituent materials of the strained layer for driving the respective mirrors. In addition, an electrostrictive material such as PMN (Pb (Mg, Nb) O ₃ ) can be used as a constituent material of the strained layer.

AMA, which is an optical path control device, is classified into a bulk device and a thin film device. The bulk optical path control device is described, for example, in US Patent Nos. 5,085,497 (issued to Gregory Um, 8 et al.), 5,159,225 (issued to Gregory Um), 5,175,465 (issued to Gregory Um, et al. And the like. The bulk optical path adjusting device is to cut a thin layer of multilayer ceramic, mount a ceramic wafer having a metal electrode formed therein in an active matrix in which a transistor is built, and then process it by sawing and then It is constructed by installing a mirror. However, since the bulk light path control device must separate the actuators by a sawing method, high precision is required in design and manufacturing, and the response speed of the deformation part is slow. Therefore, a thin film type optical path control apparatus that can be manufactured using a semiconductor manufacturing process has been developed. Such a thin film type optical path control device is disclosed in Patent Application No. 96-52681 (name of the invention: a method of manufacturing a thin film type optical path control device) filed by the applicant to the Korean Patent Office.

FIG. 1 illustrates a plan view of a membrane of the thin film type optical path adjusting device described in the above prior application, and FIG. 2 illustrates a cross-sectional view taken along line A′A ′ of the apparatus shown in FIG. 1.

1 and 2, the thin film type optical path adjusting device includes an active matrix 1 and an actuator 60 formed on the active matrix 1. The active matrix 1 includes a drain pad 5 formed on one side of the active matrix 1, a protective layer 10 stacked on the active matrix 1 and the drain pad 5, and a protective layer ( 10) includes an etch stop layer 15 stacked on top.

One end of the actuator 40 is in contact with a portion where the drain pad 5 is formed at the bottom of the etch stop layer 15 and the other side is formed in parallel with the etch stop layer 15 through the air gap 20. The membrane 25 having a, a lower electrode 30 stacked on top of the membrane 25, a strained layer 35 stacked on top of the lower electrode 30, has a stripe 55 on one side of the strained layer ( An upper electrode 40 stacked on an upper portion of the 35, and a via contact 50 formed in the via hole 45 formed vertically from one side of the strained layer 35 to the drain pad 5. .

As shown in FIG. 1, the plane of the membrane 25 has a rectangular concave portion at one side thereof, and the rectangular concave portion is stepped wider toward both edges. In addition, the other side of the membrane 25 is formed with projections narrowing stepwise from both edges toward the center so as to correspond to the stepped concave portion of the membrane of the adjacent actuator. Thus, the protrusion of the membrane 25 is fitted into the concave portion of the membrane of the adjacent actuator, and the protrusion of the membrane of the adjacent actuator is formed into the concave portion of the membrane 25.

Hereinafter, a method of manufacturing the above-described thin film type optical path control apparatus will be described with reference to the drawings.

3A to 3D show a manufacturing process diagram of the thin film type optical path control device. Referring to FIG. 3A, an M × N (M, N is an integer) MOS transistor (not shown) is built therein and a protective layer is formed on an active matrix 1 having a drain pad 5 formed on one side thereof. To form (10). The protective layer 10 is formed of Phosphor-Silicate Glass (PSG) to have a thickness of about 1.0 to about 2.0 μm using a chemical vapor deposition (CVD) method. The protective layer 10 prevents damage to the active matrix 1 in which the transistor is embedded during subsequent processing. Subsequently, an etch stop layer 15 is stacked on the protective layer 10. The etch stop layer 15 is formed to have a thickness of about 1000 to 2000 kPa using a low pressure chemical vapor deposition (LPCVD) method. The etch stop layer 15 prevents the active matrix 1 and the protective layer 10 from being etched during the subsequent etching process.

The sacrificial layer 18 is stacked on the etch stop layer 15. The sacrificial layer 18 is formed of amorphous silicon so as to have a thickness of about 1.0 to about 2.0 μm using a sputtering method. Subsequently, a portion of the sacrificial layer 18 in which the drain pad 5 is formed is patterned to expose a portion of the etch stop layer 15.

Referring to FIG. 3B, the membrane 25 is stacked on the exposed etch stop layer 15 and the sacrificial layer 18. The membrane 25 is formed to have a thickness of about 0.1 to 1.0 탆 using a sputtering method. Subsequently, the lower electrode 30 is formed on the membrane 25 using tantalum (Ta), platinum (Pt), or the like. The lower electrode 30 is laminated to have a thickness of about 500 to 2000 micrometers by using a sputtering method. A first signal (image signal) is externally applied to the lower electrode 30 through the transistor and the drain pad 5 embedded in the active matrix 1.

Referring to FIG. 3C, a strained layer 35 is stacked on the lower electrode 30. The strained layer 35 is formed so that a piezoelectric material such as PZT, PLZT, or ZnO has a thickness of about 0.1 to 1.0 mu m, preferably about 0.4 mu m, using a sputtering method. Subsequently, the upper electrode 40 is stacked on the deformation layer 35. The upper electrode 40 is formed to have a thickness of about 500 ~ 2000Å by using a sputtering method of platinum. A second signal (bias signal) is applied to the upper electrode 40 through a common electrode line (not shown) from the outside, and at the same time, the upper electrode 40 reflects light incident from a light source (not shown). Also performs a function. Subsequently, the upper electrode 40 is patterned into a predetermined pixel shape to form a stripe 55 that uniformly operates the upper electrode 40 on one side of the upper electrode 40 to prevent diffuse reflection of incident light. do.

Referring to FIG. 3D, the strain layer 35, the lower electrode 30, the membrane 25, the etch stop layer 15, and the protective layer 10 are sequentially etched from one upper side of the strain layer 35 to drain pads. The via hole 45 is formed so that a part of (5) is exposed. Subsequently, a via contact 50 is formed in the via hole 45 so that the lower electrode 30 and the drain pad 5 are connected by sputtering a tungsten (W) or titanium (Ti). Accordingly, the first signal may be applied to the lower electrode 30 through the transistor, the drain pad 5, and the via contact 50 embedded in the active matrix 1 from the outside.

Subsequently, the membrane 25 is patterned into a predetermined pixel shape, and then the sacrificial layer 18 is etched using hydrogen fluoride (HF) vapor to align the air gap 20 at the position of the sacrificial layer 18. Is formed. Then, the device formed as described above is cleaned and dried to complete the thin film type optical path control device as shown in FIG.

In the above-described thin film type optical path adjusting device, when a first signal is applied to the lower electrode 30 and a second signal is applied to the upper electrode 40, an electric field is formed between the upper electrode 40 and the lower electrode 30. Occurs. The strained layer 35 causes deformation by this electric field. The strained layer 35 contracts in a direction perpendicular to the electric field, and thus the actuator 60 is bent in the direction opposite to the direction in which the membrane 25 is formed. Since the upper electrode 40 formed on the actuator 60 also functions as a mirror, the upper electrode 40 is inclined at a predetermined angle according to the deformation of the deformation layer 35. Therefore, the light incident from the light source is reflected by the upper electrode 40 inclined at a predetermined angle, and then is projected onto the screen to form an image.

However, in the above-described thin film type optical path control apparatus, the upper electrode is formed by using platinum having excellent etching resistance but low reflectance, so that the light efficiency of the reflected light is lowered. That is, when the sacrificial layer is etched and removed, the upper portion of the upper electrode serving as the mirror is prevented from being partially etched by the hydrogen fluoride vapor, so that the hydrogen fluoride is higher than that of aluminum having a higher etching rate with respect to hydrogen fluoride. Although platinum having a low etching rate is used, platinum has a problem in that light efficiency is lowered because of lower reflectivity than aluminum.

Accordingly, the present invention provides a thin film type optical path control apparatus capable of improving the light efficiency of light incident from a light source by forming an actuator having a top electrode composed of a plurality of layers of aluminum having excellent reflectivity, platinum having excellent etching resistance, and tantalum having excellent electrical conductivity. And to provide a method for producing the same.

1 is a plan view of a membrane of the thin film type optical path control device previously applied by the applicant.

2 is a cross-sectional view taken along line A-A 'of the apparatus shown in FIG.

3A to 3D are manufacturing process diagrams of the apparatus shown in FIG. 2.

Figure 4 is a plan view of the support layer of the thin film type optical path control apparatus according to the present invention.

FIG. 5 is a cross-sectional view of the apparatus shown in FIG. 4 taken along line B′B ′.

6A to 6E are manufacturing process diagrams of the apparatus shown in FIG.

<Explanation of symbols for main parts of drawing>

100: active matrix 103: transistor

125: first metal layer 130: first protective layer

135: second metal layer 140: second protective layer

145: etch stop layer 150: sacrificial layer

155: support layer 160: lower electrode

165 strain layer 170 upper electrode

170a: first upper electrode layer 170b: second upper electrode layer

170c: third upper electrode layer 175: via hole

180: via contact 185: stripe

200: actuator

In order to achieve the above object of the present invention, the present invention provides a thin film type optical path control apparatus including an active matrix in which M x N transistors are embedded and an actuator formed on the active matrix. The active matrix further includes a first metal layer extending from the transistor and having a drain pad. The actuator may include a support layer formed on the first metal layer and the active matrix, a lower electrode formed on the support layer, a strain layer formed on the lower electrode, and a first upper electrode layer formed on the strain layer. And an upper electrode having a second upper electrode layer and a third upper electrode layer.

In addition, in order to achieve the above object of the present invention, the present invention provides an active matrix containing M × N transistors, forming a first metal layer extending from the transistor and including a drain pad, and Iii) forming a support layer on top of the first metal layer and the active matrix, ii) forming a bottom electrode on top of the support layer, iii) forming a strained layer on top of the bottom electrode, and iii) It provides a method of manufacturing a thin film type optical path control device comprising the step of forming an actuator comprising the step of forming an upper electrode having a first upper electrode layer, a second upper electrode layer and a third upper electrode layer on the deformation layer.

In the above-described thin film type optical path control device according to the present invention, the first signal (image signal) transmitted through the pad of the TCP and the pad of the AMA panel is connected to the transistor embedded in the active matrix, the drain pad of the first metal layer, and the via contact. It is applied to the lower electrode through. At the same time, a second signal (bias signal) is applied from the common electrode line to the upper electrode through the pad of the TCP and the pad of the AMA panel to generate an electric field between the upper electrode and the lower electrode. By this electric field, the strained layer between the upper electrode and the lower electrode causes deformation. The strained layer contracts in a direction orthogonal to the electric field, whereby the actuator including the strained layer is bent upward at a predetermined angle. The upper electrode, which also performs the function of a mirror that reflects the incident light, is inclined together with the actuator because it is formed on the top of the actuator. Accordingly, the upper electrode reflects light incident from the light source at a predetermined angle, and the reflected light flux passes through the slit to form an image on the screen.

According to the optical path control apparatus and the manufacturing method thereof according to the present invention, by forming the upper electrode having three layers, such as the first upper electrode layer, the second upper electrode layer, and the third upper electrode layer, the third upper electrode layer is a sacrificial layer Even if damaged during removal, the second upper electrode layer compensates for the damage of the third upper electrode layer so that there is no problem in reflecting the incident light of the upper electrode, thereby improving light efficiency. Further, the first upper electrode layer may be formed under the second upper electrode layer to generate a sufficient electric field between the upper electrode and the lower electrode even if the third upper electrode layer is damaged, thereby improving the performance of the device.

Hereinafter, a thin film type optical path adjusting apparatus according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

4 is a plan view showing a support layer of the thin film type optical path control device according to the present invention, and FIG. 5 is a cross-sectional view taken along line B′B ′ of the device shown in FIG. 4.

4 and 5, the thin film type optical path adjusting device according to the present invention includes an active matrix 100 having M × N (M, N is an integer) MOS transistors 103 and an upper portion of the active matrix 100. It includes an actuator 200 formed.

The active matrix 100 is formed on the transistor 103 and extends from the transistor 103 to include a drain pad, the first metal layer 125, and the transistor 103. The first passivation layer 130 formed on the upper portion, the second metal layer 135 formed on the first passivation layer 130, the second passivation layer 140 formed on the second metal layer 135, and the second The etch stop layer 145 is formed on the passivation layer 140.

The actuator 200 is in contact with a portion of the etch stop layer 145 where the drain pad of the first metal layer 125 is formed, and the other side is formed in parallel with the etch stop layer 145 through the air gap 190. A support layer 155 having a cross section, a lower electrode 160 formed on the support layer 155, a strain layer 165 formed on the lower electrode 160, and an upper electrode 170 formed on the strain layer 165. ), Through the strained layer 165, the lower electrode 160, the support layer 155, the etch stop layer 145, the second protective layer 140, and the first protective layer 130 from one side of the strained layer 165. The via contact 180 may be formed in the via hole 175 vertically formed to the drain pad of the first metal layer 125. The upper electrode 170 may include a first upper electrode layer 170a, a second upper electrode layer 170b formed on the first upper electrode layer 170a, and a third upper electrode layer formed on the second upper electrode layer 170b. And a stripe 185 formed at one side of the upper electrode 170 to uniformly operate the upper electrode 170 to prevent diffuse reflection of incident light.

In addition, referring to FIG. 4, one side of the plane of the support layer 155 has a concave portion having a rectangular shape at the center thereof, and the concave portion is formed to have a stepped shape toward both edges. The other side of the plane of the support layer 155 has a rectangular protrusion that narrows stepwise toward the center portion corresponding to the concave portion. Therefore, the concave portion of the support layer of the actuator adjacent to the concave portion of the support layer 155 is fitted, and the rectangular projection is fitted into the concave portion of the adjacent support layer.

Hereinafter, a method of manufacturing a thin film type optical path control device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

6A to 6E are manufacturing process diagrams of the apparatus shown in FIG. In Figs. 6A to 6D, the same reference numerals are used for the same members as in Fig. 5.

Referring to FIG. 6A, a first metal layer 105 is formed on an active matrix 100 in which M × N MOS transistors 103 are embedded. The active matrix 100 is made of a semiconductor such as silicon or an insulating material such as glass or alumina (Al ₂ O ₃ ). The transistor 103 receives a first signal from the outside to perform a switching operation. The first metal layer 105 is formed such that titanium (Ti), titanium nitride (TiN), tungsten, and nitride are sequentially stacked using a sputtering method to have a thickness of about 1000 to 1200 Å. The first metal layer 105 prevents silicon from diffusing upward in the active matrix 100, and includes a drain pad extending from the drain of the transistor 103 to transmit a first signal applied from the outside to the transistor 103. From to the via contact 180.

Referring to FIG. 6B, a first passivation layer 130 is formed on the first metal layer 125 and the transistor 103. The first protective layer 130 is formed to have a thickness of about 4000 to 6000 GPa by using the silicate glass (PSG) chemical vapor deposition (CVD) method. The first protection layer 130 protects the transistor 103 and the first metal layer 125 embedded in the active matrix 100. The second metal layer 135 is formed on the first passivation layer 130. The second metal layer 135 is formed by sequentially depositing titanium and titanium nitride by using a physical vapor deposition method (PVD) to have a thickness of about 1500 to 2000 microseconds. Since the light incident from the light source is incident on not only the upper electrode 170 that is a reflective layer but also a portion other than the portion where the upper electrode 170 is formed, the second metal layer 135 has a photo current in the active matrix 100. Flows to prevent the device from malfunctioning. Subsequently, a part of the first passivation layer 130 is formed by patterning a portion of the second metal layer 135 where the via contact 180 is to be formed in a subsequent process to form a hole in the second metal layer 135. Expose

The second passivation layer 140 is stacked on the exposed first passivation layer 130 and the second metal layer 135. The second protective layer 140 is formed of a silicate glass (PSG) to have a thickness of about 2000 kPa using a chemical vapor deposition method. The second protective layer 140 prevents damage to the active matrix 100 including the transistor 103, the first metal layer 125, and the second metal layer 135 during subsequent processing. An etch stop layer 145 is stacked on the second passivation layer 140. The etch stop layer 145 is formed to have a thickness of about 1000 to 2000 microns using a low pressure chemical vapor deposition (LPCVD) method. The etch stop layer 145 prevents a structure formed on the active matrix 100 from being etched and damaged during a subsequent etch process.

The sacrificial layer 150 is stacked on the etch stop layer 145. The sacrificial layer 150 is formed of phosphorus silicate glass (PSG) having a high concentration of phosphorus to have a thickness of about 0.5 to about 2.0 μm by using an atmospheric pressure chemical vapor deposition (APCVD) method. In this case, since the sacrificial layer 150 covers the upper portion of the active matrix 100 in which the transistor 103 is embedded, the surface flatness is very poor. Therefore, the surface of the sacrificial layer 150 is planarized by polishing the top of the sacrificial layer 150 using a spin on glass (SOG) method or a chemical mechanical polishing (CMP) method. Subsequently, a portion of the sacrificial layer 150 in which the hole of the second metal layer 135 is formed is patterned in consideration of the position where the support portion of the actuator 200 is to be formed to expose a portion of the etch stop layer 145. .

Referring to FIG. 6C, the third layer 154 may be stacked on top of the exposed etch stop layer 145 and on top of the sacrificial layer 150. The third layer 154 is formed to have a thickness of about 0.01 to 1.0 탆 using a low pressure chemical vapor deposition (LPCVD) method of a hard material such as nitride or metal. The third layer 154 is later patterned with a support layer 155 that supports the actuator 200. Subsequently, a lower electrode layer 159 is stacked on the third layer 154. The lower electrode layer 159 is about 1.0-1 .0 μm using a sputtering method or a chemical vapor deposition method for a metal having electrical conductivity such as platinum, tantalum (Ta), or platinum-tantalum (Pt-Ta). It is formed to have a thickness of. In addition, in order to separate the lower electrode layer 159 for each pixel, the lower electrode layer 159 is iso-cutted in parallel with the direction in which the actuator 200 is formed. The lower electrode layer 159 is later patterned into the lower electrode 160 to which the first signal is applied.

A fourth layer 164 made of a piezoelectric material such as ZnO, PZT, or PLZT is stacked on the lower electrode layer 159. The fourth layer 164 is formed to have a thickness of about 0.1 to 1.0 mu m, preferably about 0.4 mu m using a sol-gel method, a sputtering method, or a chemical vapor deposition method. The fourth layer 164 is subjected to a phase change by heat treatment using a rapid thermal annealing (RTA) method, and then the piezoelectric material constituting the fourth layer 164 is polarized. The fourth layer 164 is later patterned with the strained layer 165 to cause deformation by an electric field generated between the upper electrode 170 and the lower electrode 160.

The first upper electrode layer 170a is stacked on the fourth layer 164. The first upper electrode layer 170a is formed to have a thickness of about 500 to 2000 kV using tantalum having excellent electrical conductivity using a sputtering method or a chemical vapor deposition method. Subsequently, a second upper electrode layer 170b is stacked on the first upper electrode layer 170a. The second upper electrode layer 170b is formed to have a thickness of about 500 to 2000 Pa by using a sputtering method or a chemical vapor deposition method of platinum having excellent etching resistance to hydrogen fluoride. The third upper electrode layer 170c is stacked on the second upper electrode layer 170b. The third upper electrode layer 170c is formed to have a thickness of about 500 to 2000 kPa using aluminum having excellent reflectivity using a sputtering method or a chemical vapor deposition method. The first upper electrode layer 170a, the second upper electrode layer 170b, and the third upper electrode layer 170c are simultaneously patterned to form an upper electrode 170 having a predetermined pixel shape. In this case, one side of the upper electrode 170, that is, the first upper electrode layer 170a, the second upper electrode layer 170b, and one side of the third upper electrode layer 170c may be operated to uniformly operate the upper electrode 170. A stripe 185 is formed to prevent diffuse reflection of the light beam incident from (not shown). The second signal is applied to the upper electrode 170 from a common electrode line (not shown). Therefore, when the first signal is applied to the lower electrode 160 and the second signal is applied to the upper electrode 170, an electric field is generated between the upper electrode 170 and the lower electrode 160. This deformation causes the deformation layer 165 to deform. The upper electrode 170 not only functions as a bias electrode but also functions as a mirror that reflects incident light. Conventionally, since the upper electrode is formed using only platinum having a low etching rate with respect to hydrogen fluoride, the reflectance of light is lowered, and thus, the light efficiency is lowered, and thus the image quality of the image projected on the screen is poor. In contrast, in the present invention, by forming the upper electrode 170 having the plurality of layers as described above, even if the third upper electrode layer 170c is damaged during the etching process, the second upper electrode layer 170b is formed of the third upper electrode layer ( The damage of the 170c may be compensated for so that the upper electrode 170 may have no difficulty in performing the function of reflecting light. In addition, the first upper electrode layer 170a is formed under the second upper electrode layer 170b so that the upper electrode 170 causes deformation of the strained layer 165 even if the third upper electrode layer 170c is damaged. It is possible to generate a sufficient electric field.

Referring to FIG. 6D, the fourth layer 164 and the lower electrode layer 159 are sequentially patterned to form a strained layer 165 and a lower electrode 160 having a predetermined pixel shape, respectively. In this case, the strained layer 165 has a slightly larger area than the upper electrode 170, and the lower electrode 160 has a slightly larger area than the strained layer 165. Subsequently, the strained layer 165, the lower electrode 160, the third layer 154, and the etch stop layer 145 from the top of the portion of the strained layer 165 where the hole of the second metal layer 135 is formed below. ), The second protective layer 140, and the first protective layer 130 are sequentially etched to form the via hole 180 to the drain pad of the first metal layer 125, and then The via contact 180 is formed by sputtering a metal having electrical conductivity such as tungsten, aluminum, or titanium therein. The via contact 180 electrically connects the first metal layer 125 and the lower electrode 160. Therefore, the image signal current applied from the outside may be applied to the lower electrode 160 through the transistor 103, the drain pad 115, and the via contact 180 embedded in the active matrix 100. Subsequently, the third layer 154 is patterned to form a support layer 155 having a pixel shape of a slightly larger area than the lower electrode 160. The support layer 155 serves as a membrane supporting the actuator of the thin film type optical path adjusting device described in the previous application.

Referring to FIG. 6E, the sacrificial layer 150 is etched using hydrogen fluoride (HF) vapor to form an air gap 190 at a position of the sacrificial layer 150, and then a cleaning and drying process is performed. Complete the AMA device.

After completing the M × N thin film type AMA devices as described above, the active matrix 100 may be sputtered or evaporated on a metal such as chromium (Cr), nickel (Ni), or gold (Au). At the bottom of the to form an ohmic contact (not shown). Then, photolithography is provided in preparation for bonding a Tape Carrier Package (TCP) (not shown) for applying a second signal to a subsequent upper electrode 170 and a first signal to the lower electrode 160. Using the method, the active matrix 100 is cut to a predetermined thickness. Subsequently, a photoresist layer (not shown) is formed over the pad of the AMA panel so that the pad of the AMA panel (not shown) has a sufficient height in preparation for TCP bonding. Subsequently, a portion of the photoresist layer on which the pad is formed is patterned to expose the pad of the AMA panel. After etching the photoresist layer and completely cutting the active matrix 100 into a predetermined shape, the pad of the AMA panel and the pad of TCP are connected with an anisotropic conductive film (ACF) (not shown) to form a thin film type AMA module. Complete the manufacture of the module.

In the above-described thin film type optical path control device according to the present invention, the first signal transmitted through the pad of the TCP and the pad of the AMA panel is the drain of the transistor 100 and the first metal layer 125 embedded in the active matrix 100. The pad and via contact 180 is applied to the lower electrode 160. At the same time, a second signal is applied from the common electrode line to the upper electrode 170 through the pad of the TCP and the pad of the AMA panel to generate an electric field between the upper electrode 170 and the lower electrode 160. Due to this electric field, the strain layer 165 between the upper electrode 170 and the lower electrode 160 causes deformation. The strained layer 165 contracts in a direction orthogonal to the generated electric field, and the actuator 200 including the strained layer 165 is bent upward at a predetermined angle. The upper electrode 170, which also functions as a mirror that reflects incident light, is inclined together with the actuator 200 because the upper electrode 170 is formed on the actuator 200. Accordingly, the upper electrode 170 reflects the light beam incident from the light source at a predetermined angle, and the reflected light beam passes through the slit to form an image on the screen.

In the optical path adjusting device and the method of manufacturing the same, an upper electrode having three layers, such as a first upper electrode layer having excellent electrical conductivity, a second upper electrode layer having excellent etching resistance, and a third upper electrode layer having excellent reflectivity, As a result, even if the third upper electrode layer is damaged while removing the sacrificial layer, the second upper electrode layer compensates for the damage of the third upper electrode layer so that there is no problem in reflecting the incident light of the upper electrode, thereby improving light efficiency. have. Furthermore, the first upper electrode layer may be formed under the second upper electrode layer to generate a sufficient electric field between the upper electrode and the lower electrode even if the third upper electrode layer is damaged.

Although the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited thereto and may be improved or modified by those skilled in the art within the scope of the technical idea of the present invention.

Claims (11)

An active matrix 100 in which M × N (M, N is an integer) transistors 103 are built-in; A first metal layer 125 extending from the transistor 103 and including a drain pad; And Iii) a support layer 155 formed on the first metal layer 125 and the active matrix 100, ii) a lower electrode 160 formed on the support layer 155, iii) a lower electrode 160 A thin film type optical path comprising an actuator 200 formed on a strained layer 165 formed on an upper portion of the strained layer 165 and an upper electrode 170 formed on the strained layer 165 and having a plurality of layers. Regulator. The apparatus of claim 1, wherein the upper electrode (170) comprises a first upper electrode layer (170a), a second upper electrode layer (170b), and a third upper electrode layer (170c). 3. The thin film type optical path adjusting device according to claim 2, wherein the first upper electrode layer (170a) is made of tantalum and has a thickness of 500 to 2000 mW. 3. The thin film type optical path adjusting device according to claim 2, wherein the second upper electrode layer (170b) is made of platinum and has a thickness of 500 to 2000 mW. 3. The thin film type optical path adjusting device according to claim 2, wherein the third upper electrode layer (170c) is made of aluminum and has a thickness of 500 to 2000 mW. The method of claim 1, wherein the actuator 200 is formed from one side of the strained layer 165 through the strained layer 165, the lower electrode 160, and the support layer 155. And a via contact (180) formed to connect the drain pad of the first metal layer (125) and the lower electrode (160) in the via hole (175) formed up to the drain pad. Providing an active matrix containing M × N (M, N is an integer) transistors; Forming a first metal layer extending from the transistor and including a drain pad; And Iii) forming a support layer on top of the first metal layer and the active matrix, ii) forming a bottom electrode on top of the support layer, iii) forming a strained layer on top of the bottom electrode, and iii) A method of manufacturing a thin film type optical path control device comprising the step of forming an actuator comprising the step of forming an upper electrode having a plurality of layers on top of the strained layer. The method of claim 7, wherein the forming of the upper electrode comprises: forming a first upper electrode layer on the lower electrode, forming a second upper electrode layer on the first upper electrode layer, and 2. The method of manufacturing a thin film type optical path control device, further comprising forming a third upper electrode layer on the upper electrode layer. The method of claim 8, wherein the forming of the first upper electrode layer is performed using a sputtering method or a chemical vapor deposition method using tantalum. The method of claim 8, wherein the forming of the second upper electrode layer is performed using a sputtering method or a chemical vapor deposition method using platinum. The method of claim 8, wherein the forming of the third upper electrode layer is performed using a sputtering method or a chemical vapor deposition method using aluminum.

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