KR100257606B1 - Thin film actuated mirror array having a tilting angle sensor and method for manufacturing the same - Google Patents

Abstract

PURPOSE: A thin film actuated mirror arrays and a method for fabricating the same are to drive an actuator at a desired drive angle by generating the proper voltage between an upper electrode and a lower electrode. CONSTITUTION: The first metal layer is formed on an active matrix(100) with an MxN transistor provided therein. The first metal layer includes a drain pad(135) and a lower displacement measuring line(145) connected to a drain(105) of the transistor, and a displacement measuring pad connected to the drain pad. An actuator(230) is formed on the first metal layer and the active matrix. The actuator includes a support layer(180), a lower electrode(185), a deformation layer(190), and an upper electrode(195). A displacement measuring member(199) is formed on the actuator, and includes a displacement measuring piezoelectric layer(196) and an upper displacement measuring line(198). The first via contact(215) connects the lower electrode and the drain pad. The second via contact connects the upper displacement measuring line and the displacement measuring pad. A mirror(200) is formed on the support layer.

Description

Thin film type optical path adjusting device equipped with displacement measuring member and manufacturing method thereof

The present invention relates to a thin film type optical path control apparatus using AMA (Actuated Mirror Arrays) and a method of manufacturing the same. More specifically, the actuator is mounted at a desired driving angle by accurately measuring the driving angle of the actuator by mounting a displacement measuring member on the upper part of the actuator. The present invention relates to a thin film type optical path control device capable of driving a light emitting device and a method of manufacturing the same.

Spatial light modulators, which are devices for projecting optical energy onto a screen, can be applied to various fields such as optical communication, image processing, and information display devices. An image processing apparatus using such an optical path adjusting device or a spatial light modulator typically has a direct-view image display device and a projection-type image device according to a method of displaying optical energy on a screen. display device).

An example of a direct-view image display device is a CRT (Cathode Ray Tube). The CRT device is called a CRT, which has excellent image quality but increases in weight and volume as the screen is enlarged, leading to an increase in manufacturing cost. There is. Examples of the projection image display apparatus include a liquid crystal display (LCD), a deformable mirror device (DMD), and an AMA. Such projection image display devices can be further divided into two groups according to their optical characteristics. That is, devices such as LCDs can be classified as transmissive spatial light modulators, while DMD and AMA can be classified as reflective spatial light modulators.

Transmission optical modulators, such as LCDs, have a very simple optical structure, which makes them thinner, lighter in weight, and smaller in volume. However, due to the polarity of the light, the light efficiency is low, there is a problem inherent in the liquid crystal material, for example, there is a disadvantage that the response speed is slow and the inside is easy to overheat. In addition, the maximum light efficiency of existing transmission light modulators is limited to a range of 1-2%, requiring dark room conditions to provide acceptable display quality. Therefore, optical modulators such as DMD and AMA have been developed to solve the above problems.

Although DMD shows a relatively good light efficiency of about 5%, the hinge structure employed in the DMD not only causes serious fatigue problems, but also requires a very complicated and expensive driving circuit. The AMA reflects the light incident from the light source at each angle installed in the mirrors, and the reflected light is projected on the screen through an aperture such as a slit or pinhole to be imaged. The device can adjust the luminous flux to bear. Therefore, its structure and operation principle are simple, and high light efficiency (10% or more) can be obtained compared to LCD or DMD. In addition, the contrast of the image projected on the screen is improved to obtain a brighter and clearer image.

Each actuator of the AMA generates a deformation in accordance with the electric field generated by the applied electric picture signal and the bias signal. As the actuator deforms, each of the mirrors mounted on top thereof is inclined. Thus, the inclined mirrors reflect the incident light at a predetermined angle to form an image on the screen. As an actuator for driving the respective mirrors, piezoelectric materials such as PZT (Pb (Zr, Ti) O ₃ ) or PLZT ((Pb, La) (Zr, Ti) O ₃ ) are used. It is also possible to configure the actuator as electrostrictive material such as PMN (Pb (Mg, Nb) O 3).

These AMA devices are largely divided into bulk type and thin film type. Bulk light path control devices are disclosed in US Pat. No. 5,085,497 to Gregory Um et al. The bulk optical path control device is made by thinly cutting a multilayer ceramic to mount a ceramic wafer having a metal electrode therein into an active matrix in which a transistor is built, and then processing by using a sawing method and installing a mirror on the top. . However, the bulk optical path control device requires very high precision in design and manufacturing, and has a disadvantage in that the response of the strained layer is slow.

Accordingly, 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. 96-42197 filed by the applicant of the Korean Patent Office on September 24, 1996 (name of the invention: thin film type optical path control device that can control the stress of the membrane and its manufacturing method). Is disclosed.

1A and 1B show a cross-sectional view of the thin film type optical path adjusting device described in the preceding application.

Referring to FIG. 1B, the thin film type optical path adjusting device includes an active matrix 1 and an actuator 60. The active matrix 1 in which M x N (M, N is an integer) MOS transistors and a drain pad 5 extending from the drain region of the transistor is formed in the active matrix 1 and the drain pad 5. The protective layer 10 stacked on top of the protective layer 10 and the etch stop layer 15 stacked on the protective layer 10 is included.

The actuator 60 is a membrane formed on one side of the etch stop layer 15 below the drain pad 5, and the other side is horizontally formed with the lower portion of the active matrix 1 via the air gap 25. 30, the lower electrode 35 stacked on the membrane 30, the strained layer 40 stacked on the lower electrode 35, and the upper electrode 45 stacked on the strained layer 40. And a lower portion in the via hole 50 formed vertically from one side of the strained layer 40 to the drain pad 5 through the lower electrode 35, the membrane 30, the etch stop layer 15, and the protective layer 10. The via 35 includes a via contact 55 formed to connect the electrode 35 and the drain pad 5 to each other.

A stripe 46 is formed on a part of the upper electrode 45. The stripe 46 operates the upper electrode 45 uniformly so that the light incident from the light source is diffusely reflected at the boundary between the portion of the upper electrode 45 which is deformed and the portion which is not deformed according to the deformation of the deforming layer 40. prevent.

Hereinafter, the manufacturing method of the above-mentioned thin film type optical path control apparatus is demonstrated with reference to FIGS. 1A-1B.

Referring to FIG. 1A, an silicate is formed on an active matrix 1 in which M x N (M, N is an integer) MOS transistors (not shown) are formed and a drain pad 5 extending from the drain region of the transistor is formed. A protective layer 10 made of glass PSG is formed. The protective layer 10 is formed to have a thickness of about 1.0 μm using a chemical vapor deposition (CVD) method. The protective layer 10 protects the active matrix 1 in which the transistor is embedded during the subsequent process.

An etch stop layer 15 made of nitride is formed on the passivation 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 protective layer 10 and the active matrix 1 from being etched during the subsequent etching process.

The sacrificial layer 20 is formed on the etch stop layer 15. The sacrificial layer 20 is formed of phosphorous silicate glass (PSG) having a high concentration of phosphorus (PG) to have a thickness of about 1.0 to 3.0 μm by using an atmospheric pressure chemical vapor deposition (APCVD) method. In this case, since the sacrificial layer 20 covers the upper portion of the active matrix 1 in which the transistor is embedded, the surface flatness is very poor. Accordingly, the surface of the sacrificial layer 20 is planarized by using spin on glass (SOG) or chemical mechanical polishing (CMP). Subsequently, a portion of the sacrificial layer 20 in which the drain pad 5 is formed is etched to expose a portion of the etch stop layer 15, thereby making a position where the support of the actuator 60 is to be formed.

The membrane 30 is formed on the exposed etch stop layer 15 and the sacrificial layer 20 to a thickness of about 0.1 to 1.0㎛. Membrane 30 is formed using low pressure chemical vapor deposition (LPCVD). At this time, the membrane 30 is formed while varying the ratio of the reaction gas in the reaction vessel at a low pressure to control the stress in the membrane 30.

On the membrane 30, a lower electrode 35 made of metal such as platinum (Pt), tantalum (Ta), platinum-tantalum, or the like is formed. The lower electrode 35 is formed to have a thickness of about 0.1 to 1.0 μm using a sputtering method. Subsequently, the lower electrode 35 is patterned to separate the lower electrode 35 for each pixel so that an independent first signal (image signal) is applied to each pixel (Iso­Cut etching process).

On the lower electrode 35, a strained layer 40 made of a piezoelectric material such as PZT or PLZT is formed. The strained layer 40 is formed to have a thickness of about 0.1 μm to about 1.0 μm, preferably about 0.4 μm using a sol-gel method, and then phase-shifted by a rapid heat treatment (RTA) method. In the strained layer 40, a second signal (bias signal) is applied to the upper electrode 45, and a first signal is applied to the lower electrode 35, according to a potential difference between the upper electrode 45 and the lower electrode 35. It is deformed by the generated electric field.

The upper electrode 45 is formed on the strained layer 40. The upper electrode 45 is formed of a metal having electrical conductivity and reflectivity, such as aluminum or platinum, to have a thickness of about 0.1 to 1.0 μm using a sputtering method. The second signal is applied to the upper electrode 45 through a common electrode line (not shown) from the outside. In addition, the upper electrode 45 also functions as a mirror that reflects light incident from the light source.

Referring to FIG. 1B, the upper electrode 45, the strained layer 40, and the lower electrode 35 are each patterned into a predetermined pixel shape. At this time, a portion of the upper electrode 45 is patterned to form a stripe 46. Subsequently, the strained layer 40, the lower electrode 35, the membrane 30, the etch stop layer 15, and the protective layer 10 are sequentially formed from one side of the strained layer 40 to the top of the drain pad 5. The via hole 50 is formed by etching. Subsequently, a metal contact such as tungsten, platinum or titanium is sputtered into the via hole 50 to form a via contact 55 connecting the drain pad 5 and the lower electrode 35 to each other. Thus, the via contact 55 is formed vertically from the lower electrode 35 to the drain pad 5 in the via hole 50. Therefore, the first signal applied from the outside is applied to the lower electrode 35 through the transistor, the drain pad 5, and the via contact 55 embedded in the active matrix 1.

Subsequently, the membrane 30 is patterned to have a predetermined pixel shape. After the air gap 25 is formed at the position of the sacrificial layer 20 by etching the sacrificial layer 20 by 49% hydrogen fluoride vapor, a cleaning and drying process is performed to remove the remaining etching solution. This completes the AMA device.

In the above-described thin film type optical path adjusting device, the first signal is applied to the lower electrode 35 through the MOS transistor, the drain pad 5, and the via contact 55 embedded in the active matrix 1. At the same time, a second signal is applied to the upper electrode 45 through the common electrode line to generate an electric field between the upper electrode 45 and the lower electrode 35. By the electric field, the strained layer 40 stacked between the upper electrode 45 and the lower electrode 35 causes deformation. The strained layer 40 contracts in a direction perpendicular to the generated electric field, and the actuator 60 including the strained layer 40 is bent upward at a predetermined angle. Therefore, the upper electrode 45 on the actuator 60 is also inclined in the same direction. Light incident from the light source is reflected by the upper electrode 45 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 device, actuators formed corresponding to M × N MOS transistors operate in an open loop with respect to a given input signal. I can not know. That is, when the actuator's driving angle is changed by various external factors such as thermal change, electrical change, or mechanical change when the actuator is driven, it is impossible to measure the change in the actuator's driving angle. . Therefore, it becomes impossible to uniformly adjust the driving angles of the actuators, which causes a problem of lowering the contrast of the image.

Accordingly, an object of the present invention is to form a displacement measuring member including a piezoelectric layer for displacement measurement and an upper displacement measurement line on the upper electrode, and separately wire the lower displacement measurement line and the displacement measurement pad to the active matrix. By connecting the displacement measuring member to the displacement measuring pad connected to the lower displacement measuring line wired to the active matrix through the second via contact, the current according to the deformation of the piezoelectric layer for displacement measurement can be measured. Therefore, when the generated current exceeds or falls below the proper range, a proper voltage can be generated between the upper electrode and the lower electrode to drive the actuator at a desired driving angle.

1A and 1B are cross-sectional views illustrating a method of manufacturing a thin film type optical path adjusting device described in the applicant's prior application.

2 is a plan view of a thin film type optical path control apparatus according to the present invention.

3 is a cross-sectional view of the device shown in FIG. 2 taken along line A′A ′.

4 is a cross-sectional view taken along line B′B ′ of the apparatus shown in FIG. 2.

5A to 9B are manufacturing process diagrams of the apparatus shown in FIGS. 3 and 4.

<Explanation of symbols for main parts of drawing>

100: active matrix 105: drain

110: source 115: gate

120: device isolation layer 125: gate line

130: source line 135: drain pad

140: displacement measurement pad 145: lower displacement measurement line

150: first metal layer 155: first protective layer

160: second metal layer 165: second protective layer

170: etch stop layer 175: sacrificial layer

180 support layer 185 lower electrode

190 strain layer 195 upper electrode

196: piezoelectric layer for displacement measurement 198: upper displacement measurement line

199: displacement measurement member 200: mirror

205: first via hole 210: second via hole

215: first via contact 220: second via contact

225: Air gap 230: Actuator

In order to achieve the above object, the present invention provides a display device comprising: (i) a source pad, a drain pad connected to a drain, and a lower displacement measuring line formed on an active matrix including M × N transistors; A first metal layer comprising: ii) an actuator formed on the first metal layer and the active matrix, the actuator including a support layer, a lower electrode, a deformation layer, and an upper electrode; A displacement measuring member comprising a displacement measuring line, iii) a first via contact connecting the lower electrode and the drain pad, iii) a second via contact connecting the upper displacement measuring line and the displacement measuring pad, and iii) an upper portion of the support layer. It provides a thin film type optical path control device including a mirror formed in the.

In addition, in order to achieve the above object, the present invention, the first metal layer is stacked on top of the active matrix containing the M × N transistors and patterned by patterning the drain line connected to the source line, drain and lower displacement measuring line and And forming a displacement measuring pad connected thereto, forming an actuator including a support layer, a lower electrode, a deformation layer, and an upper electrode on the first metal layer and the active matrix, and a piezoelectric layer for displacement measurement on the actuator. And forming a displacement measuring member including an upper displacement measuring line, forming a first via contact connecting the lower electrode and the drain pad, and forming a second via contact connecting the upper displacement measuring line and the displacement measuring pad. Forming, and forming a mirror on top of the support layer of the manufacturing method of the thin film type optical path control apparatus to provide.

According to the thin film type optical path adjusting device and the manufacturing method thereof according to the present invention, a displacement measuring member including a piezoelectric layer for measuring displacement and an upper displacement measuring line is formed on the upper electrode, and a lower displacement measuring line and a displacement measuring pad are formed. Wire to the active matrix separately. By connecting the displacement measuring member to the displacement measuring pad connected to the lower displacement measuring line wired to the active matrix through the second via contact, the current according to the deformation of the piezoelectric layer for displacement measurement can be measured. Therefore, when the generated current exceeds or falls below the proper range, a proper voltage can be generated between the upper electrode and the lower electrode to drive the actuator at a desired driving angle.

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

2 is a plan view of a thin film type optical path control device according to the present invention, Figure 3 is a cross-sectional view taken along the line AA 'of the device shown in Figure 2, Figure 4 is a BB of the device shown in Figure 2 It shows a cross-sectional view cut in line.

2 to 4, the above-described thin film type optical path adjusting device according to the present invention includes an active matrix 100, an actuator 230, a displacement measuring member 199, and a mirror 200.

The active matrix 100 includes an isolation layer 120 for dividing the active matrix 100 into an active region and a field region, and a gate 115, a source 110, a drain 105, and a common electrode pad in the active region. And M × N MOS transistors formed with 140. In addition, the active matrix 100 is stacked on top of the MOS transistor and is connected to the gate line 125 connected to the gate 115, the source line 130 connected to the source 110, and the drain pad connected to the drain 105. A first metal layer 150 including a lower displacement measuring line 145 connected to the 135 and a displacement measuring pad 140, a first protective layer 155 stacked on top of the first metal layer, and a first protective layer A second metal layer 160 stacked on top of the layer, a second passivation layer 165 stacked on top of the second metal layer, and an etch stop layer 170 stacked on top of the second passivation layer. Here, the second metal layer 160 includes a titanium (Ti) layer and a titanium nitride (TiN) layer.

Referring to FIGS. 3 and 4, the actuator 230 has one side in contact with a portion of the etch stop layer 170 in which the drain pad 135 is formed, and the other side thereof has an active matrix 100 through the air gap 225. ) The support layer 180 formed horizontally with the bottom of the lower layer, the lower electrode 185 formed on the upper portion of the support layer 180, the strained layer 190 formed on the lower electrode 185, and the upper portion of the strained layer 190. And formed upper electrode 195.

A displacement measuring member 199 including a piezoelectric layer 196 for measuring displacement and an upper displacement measuring line 198 is formed on the actuator 230.

The actuator 230 includes a strained layer 190, a lower electrode 185, a support layer 180, an etch stop layer 170, a second protective layer 165, and a first protective layer 155 from one side of the strained layer 190. The first via contact 215 is formed to connect the lower electrode 185 and the drain pad 135 to the inside of the first via hole 205 formed vertically through the drain pad 135. An upper displacement measuring line 198, a piezoelectric layer 196 for displacement measurement, a support layer 180, an etch stop layer 170, a second protective layer 165, and a first protective layer 155 from one side of the line 198. The second via contact 220 is formed to connect the upper displacement measuring line 198 and the displacement measuring pad 140 to the inside of the second via hole 210 vertically formed to the displacement measuring pad 140 through the through hole. do. Preferably, the first via hole 205 and the second via hole 210 are performed at the same time. The upper electrode 195, the strain layer 190, and the lower electrode 185 of the portion where the second via contact 220 is formed are previously patterned so that the second via contact 220 is not in contact with the second via contact 220. Therefore, the lower electrode 185 is connected to the drain pad 135 through the first via contact 215, and the upper displacement measuring line 198 is connected to the lower displacement measuring line 145 through the second via contact 220. It is connected to this connected displacement measuring pad 140. The support layer 180 of the present invention performs the function of the membrane described in the preceding application.

The support layer 180 has a shape in which a rectangular flat plate is integrally formed with the arms on the same plane between two rectangular arms formed in parallel from both support portions. The mirror 200 is formed on the rectangular flat plate of the support layer 180. Thus, the mirror 200 has the shape of a rectangular flat plate.

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

5a to 9b show a manufacturing process of the thin film type optical path control apparatus according to the present invention.

FIG. 5A is a cross-sectional view of the active matrix along line AA ′ of FIG. 3 showing a state after patterning a first metal layer in the device according to the invention, and FIG. 5B shows a state after patterning the first metal layer. 5B is a plan view of an active matrix showing a state after patterning a first metal layer in the apparatus according to the present invention.

5A, 5B and 5C, after preparing an active matrix 100 composed of an n-type doped silicon (Si) substrate, a conventional device isolation process, such as local oxidation of silicon; A device isolation layer 120 is formed in the active matrix 100 to classify the active region and the field region using the LOCOS. Subsequently, a gate 115 made of a conductive material such as polysilicon doped with impurities is formed on the active region, and then a p ⁺ source 110 and a drain 105 are formed by an ion implantation process, thereby forming M x. N (M, N is an integer) to form MOS transistors.

After the insulating film 112 made of oxide is formed on the resultant transistor, the openings exposing the top of one side of the gate 115, the source 110, and the drain 105 are formed by a photolithography process. Subsequently, the first metal layer 150 made of a metal such as tungsten (W) is deposited on the top of the resultant product in which the openings are formed, and then the first metal layer 150 is patterned by a photolithography process to thereby connect the source 110 to the source 110. A drain pad 135 is formed that is connected to the line 130 and the drain 105. At the same time, a displacement measuring pad 140 is formed at a portion adjacent to the drain pad 135 and the gate line 125, and is a lower displacement measuring line parallel to the source line 130 and connected to the displacement measuring pad 140. 145 is formed. Subsequently, an insulating film 112 made of oxide is formed on one side of the gate 115, the source line 130, and the lower displacement measurement line 145. The first metal layer is stacked on the portion where the insulating layer 112 is formed, and then patterned to form a gate line 125 connected to the gate 115. The first signal (image signal) applied from the outside is transferred to the lower electrode 185 through the MOS transistor and the drain pad 135 embedded in the active matrix 100.

6A and 6B are diagrams illustrating a state in which the lower electrode layer 184 is formed.

6A and 6B, a first protective layer 155 is formed on the first metal layer 150 to protect the active matrix 100 in which the MOS transistors are embedded. The first passivation layer 155 is formed to have a thickness of about 8000 GPa by using the silicate glass PSG using a chemical vapor deposition (CVD) method. The first protective layer 155 prevents damage to the active matrix 100 in which the MOS transistor is embedded during the subsequent process.

The second metal layer 160 is formed on the first passivation layer 155. In order to form the second metal layer 160, first, a titanium layer is formed by sputtering titanium (Ti) to a thickness of about 300 μm. Subsequently, titanium nitride is deposited on top of the titanium layer using a physical vapor deposition (PVD) method to form a titanium nitride layer. The second metal layer 160 prevents light leakage current from flowing through the active matrix 100 because light incident from the light source is incident not only to the mirror 200 but also to a portion other than the portion where the mirror 200 is formed. . Subsequently, in the subsequent process of the second metal layer 160, portions in which the first via contact 215 and the second via contact 220 are to be formed are etched through a photolithography process to form openings in the second metal layer 160. .

The second passivation layer 165 is formed on the second metal layer 160. The second protective layer 165 is formed to have a thickness of about 2000 GPa using phosphorus silicate glass (PSG). The second protective layer 165 also prevents damage to the active matrix 100 in which the MOS transistor is embedded and the results formed on the active matrix 100 during the subsequent process.

An etch stop layer 170 is formed on the second passivation layer 165. The etch stop layer 170 prevents the active matrix 100 and the second passivation layer 165 from being etched due to the subsequent etching process. The etch stop layer 170 is formed by depositing nitride (Si ₃ N ₄ ) by a low pressure chemical vapor deposition (LPCVD) method to have a thickness of about 1000 to 2000 kPa.

The sacrificial layer 175 is formed on the etch stop layer 170. The sacrificial layer 175 is formed of phosphorous silicate glass (PSG) using an atmospheric pressure chemical vapor deposition (APCVD) method. 0 to 3. It is formed by depositing at a thickness of about 0㎛. In this case, since the sacrificial layer 175 covers the upper portion of the active matrix 100 in which the MOS transistor is embedded, the surface flatness is very poor. Accordingly, the surface of the sacrificial layer 175 is planarized by using spin on glass (SOG) or chemical mechanical polishing (CMP) to polish the surface of the sacrificial layer 175 to a thickness of about 1 μm. .

Subsequently, two portions of the sacrificial layer 175 having the opening of the second metal layer 160 are etched to expose a portion of the etch stop layer 170, thereby forming an anchor, which is a support of the actuator 230. Make a location.

The first layer 179 is formed on the exposed etch stop layer 170 and on the sacrificial layer 175. The first layer 179 is formed to have a thickness of about 0.1 to 1.0 탆 using low pressure chemical vapor deposition (LPCVD). The first layer 179 is later patterned into the support layer 180.

The lower electrode layer 184 is formed on the first layer 179 using a metal such as platinum, tantalum, or platinum-tantalum (Pt-Ta), which is a metal having excellent electrical conductivity. The lower electrode layer 184 is formed to have a thickness of about 0.01 to 1.0 µm using a sputtering method. Subsequently, the portion of the lower electrode layer 184 having the displacement measuring pad 140 formed thereon is etched, and at the same time, the periphery of the portion where the second via contact 220 is to be formed is etched larger than the second via contact 220. The first layer 179 is exposed. By separating the lower electrode layer 184 for each pixel, an independent first signal is applied to each pixel (Iso­Cut process). The lower electrode layer 184 is later patterned into the lower electrode 185. The first signal transferred from the transistor embedded in the active matrix 100 is applied to the lower electrode 185.

7A and 7B are diagrams illustrating a state in which the lower electrode 185 is formed.

7A and 7B, a second layer is stacked on the lower electrode layer 184. The second layer is formed using a piezoelectric material such as PZT or PLZT so as to have a thickness of 0.1 to 1.0 mu m, preferably about 0.4 mu m. The second layer is formed using a sol-gel method, a sputtering method, or a chemical vapor deposition (CVD) method, and then subjected to a phase change by heat treatment using a rapid heat treatment (RTA) method. Subsequently, the first layer 179 is exposed by etching a portion of the second layer in which the second via contact 220 is to be formed to be narrower than the lower electrode layer 184 in a patterned pattern of the lower electrode layer 184. The second layer is later patterned into a strained layer 190. The strained layer 190 is applied to an electric field generated by a second signal applied to the upper electrode 195 and a first signal applied to the lower electrode 185 according to a potential difference between the upper electrode 195 and the lower electrode 185. Cause deformation.

An upper electrode layer is stacked on top of the second layer. The upper electrode layer is formed of a metal having electrical conductivity and reflectivity, such as platinum, aluminum, or silver, to have a thickness of about 0.01 to 1.0 탆 using a sputtering method. Subsequently, the first layer 179 is exposed by etching the peripheral portion of the upper electrode layer in which the second via contact 220 is to be formed to be narrower than the second layer in a patterned pattern of the second layer. At the same time, the periphery of the portion of the upper electrode layer where the first via contact 215 is to be formed is etched to expose the second layer. The upper electrode layer is later patterned into the upper electrode 195.

The piezoelectric layer 196 for displacement measurement is formed on the upper electrode layer. The piezoelectric layer 196 for displacement measurement is formed using a piezoelectric material such as PZT or PLZT similarly to the strained layer 190. The piezoelectric layer 196 for displacement measurement is formed by using a sol-gel method, a sputtering method, or a chemical vapor deposition (CVD) method, and then subjected to a phase change by heat treatment using a rapid heat treatment (RTA) method. Subsequently, the upper electrode layer is patterned around the portion of the displacement measurement piezoelectric layer 196 on which the first via contact 215 is to be formed to be narrower than the upper electrode layer to expose the second layer.

An upper displacement measuring metal layer is formed on the piezoelectric layer 196 for displacement measurement. The upper displacement measurement metal layer is formed using platinum, tantalum, platinum-tantalum, aluminum, or silver. The upper displacement measuring metal layer is formed using a sputtering method or a chemical vapor deposition method.

After applying the first photoresist (not shown) to the upper portion of the upper displacement measuring metal layer by spin coating, the upper displacement measuring metal layer has a mirror-shaped 'C' shape as shown in FIG. 2. Patterned to form the upper displacement measurement line 198. Subsequently, after the first photoresist is removed, a second photoresist (not shown) is applied on the patterned upper displacement measuring line 198 and the piezoelectric layer 196 for displacement measurement by spin coating, and then displaced. The piezoelectric layer 196 for measurement is patterned to have a mirror-shaped 'c' shape slightly wider than the upper displacement measuring line 198 to complete the displacement measuring member 199 (see FIG. 2). Subsequently, after removing the second photoresist and applying a third photoresist (not shown) on the upper displacement measuring line 198, the piezoelectric layer 196 for displacement measurement, and the upper electrode layer by spin coating, The upper electrode layer is patterned to have a mirror-shaped 'c' shape slightly wider than the piezoelectric layer 196 for displacement measurement to form the upper electrode 195. After removing the third photoresist and applying a fourth photoresist (not shown) on the displacement measuring member 199, the upper electrode 195, and the second layer by spin coating, the second layer is applied to the upper electrode. The strained layer 190 may be formed by patterning the mirror to have a shape of 'c' slightly wider than the width of 195. After removing the fourth photoresist and applying a fifth photoresist (not shown) on the displacement measuring member 199, the upper electrode 195, the deformation layer 190, and the lower electrode layer by spin coating, The lower electrode layer is patterned to have a mirror-shaped 'c' shape slightly wider than the deformation layer 190 to form the lower electrode 185.

8A and 8B are diagrams illustrating a state in which the first via contact 215 and the second via contact 220 are formed.

8A and 8B, a portion of the strain layer 190 in which the drain pad 135 is formed is etched to form a first via hole 205. At the same time, a portion of the upper displacement measuring line 198 in which the displacement measuring pad 140 is formed is etched to form a second via hole 210. That is, the strained layer 190, the lower electrode 185, the first layer 179, the etch stop layer 170, the second passivation layer 165, and the first passivation layer 155 are sequentially etched to form the strain layer ( The first via hole 205 is formed from one side of the 190 to the drain pad 135. At the same time, the upper displacement measuring line 198, the piezoelectric layer 196 for displacement measurement, the first layer 179, the etch stop layer 170, the second protective layer 165, and the first protective layer 155 are disposed. Etching is sequentially performed to form a second via hole 210 from one side of the upper displacement measuring line 198 to the displacement measuring pad 140 to which the lower displacement measuring line 145 is connected. Subsequently, the first via contact is connected to the drain pad 135 and the lower electrode 185 by sputtering a metal such as tungsten (W), platinum, aluminum, or titanium into the first via hole 205. 215 is formed. Similarly, the displacement measuring pad 140 and the upper displacement measuring line 198 may be connected to the inside of the second via hole 210 by sputtering a metal such as tungsten (W), platinum, aluminum, or titanium. The second via contact 220 is formed. Since the lower electrode 185 of the portion where the second via contact 220 is formed is patterned in an arc shape larger than the second via contact 220, the second via contact 220 does not contact the lower electrode 185. .

9A and 9B are views illustrating a state in which the mirror 200 is formed.

9A and 9B, a sixth photoresist (not shown) is applied on the patterned lower electrode 185, the first via contact 215, and the second via contact 220 by spin coating. Afterwards, a portion extending from both support portions of the first layer 179 has a shape of a rectangle that is slightly wider than the lower electrode 185, and a central portion of the first layer 179 formed integrally therewith has a shape of a rectangular flat plate. It is patterned to have a support layer 180 is formed. That is, as shown in FIG. 2, the support layer 180 has rectangular arms extending from both support portions, and a rectangular flat plate having a wider area between the arms is formed integrally with the arms on the same plane. . Then, the sixth photoresist is removed. As a result of the patterning of the support layer 180 as described above, a portion of the sacrificial layer 175 is exposed.

After applying a seventh photoresist (not shown) on the exposed sacrificial layer 175 and the upper portion of the support layer 180 by spin coating, patterning is performed so that a rectangular flat plate, which is the center of the support layer 180, is exposed. do. In addition, a sputtering method or a chemical vapor deposition method is used to form a metal having reflective properties such as silver, platinum, or aluminum on the upper portion of the center portion of the rectangular exposed support layer 180 to a thickness of about 0.3 to 2.0 µm. By deposition. Subsequently, the deposited metal is patterned so that the deposited metal has the same shape as the center portion of the rectangular exposed support layer 180 to form the mirror 200, and then the seventh photoresist is removed.

Subsequently, the sacrificial layer 175 is removed using hydrogen fluoride (HF) vapor to form an air gap 225 at the position of the sacrificial layer 175, followed by rinsing and drying to form a thin film type optical path. Complete the adjustment.

In the above-described thin film type optical path control device according to the present invention, the first signal is applied to the lower electrode 185 through the transistor, the drain pad 135 and the first via contact 215 embedded in the active matrix 100. . At the same time, the second signal is applied to the upper electrode 195 through the common electrode line, thereby generating an electric field according to the potential difference between the upper electrode 195 and the lower electrode 185. Due to this electric field, The strained layer 190 formed between the lower electrodes 185 causes strain. The strained layer 190 contracts in a direction perpendicular to the generated electric field, and thus includes the strained layer 190 and the support layer 180. The actuator 230 is bent at a predetermined angle, at this time, the piezoelectric layer 196 for measuring displacement formed on the upper electrode 195 also generates charge while deforming, and the generated charge is measured for upper displacement. Flows in line 198. The charge generated by the deformation of the piezoelectric layer 196 for displacement measurement is transmitted to the lower displacement measurement line 145 through the second via contact 220 and the displacement measurement pad 140, The amount of charge is measured and the actuator 230 Therefore, when the generated current exceeds or falls below the proper range, an appropriate voltage can be generated between the upper electrode and the lower electrode to drive the actuator at a desired driving angle. The driving angles of the actuators may be uniformized, and the mirror 200 reflecting the light incident from the light source may be bent at the same angle as the actuator 230 because the mirror 200 is formed above the central portion of the support layer 180. The mirror 200 reflects the incident light at a predetermined angle, and the reflected light passes through the slit to be projected onto the screen to form an image.

According to the thin film type optical path adjusting device and the manufacturing method thereof according to the present invention, a displacement measuring member including a piezoelectric layer for measuring displacement and an upper displacement measuring line is formed on the upper electrode, and a lower displacement measuring line and a displacement measuring pad are formed. Wire to the active matrix separately. By connecting the displacement measuring member to the displacement measuring pad connected to the lower displacement measuring line wired to the active matrix through the second via contact, the current according to the deformation of the piezoelectric layer for displacement measurement can be measured. Therefore, when the generated current exceeds or falls below the proper range, a proper voltage can be generated between the upper electrode and the lower electrode to drive the actuator at a desired driving angle.

As described above, although described with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified without departing from the spirit and scope of the invention described in the claims below. And can be changed.

Claims (4)

A drain pad 135 and a lower displacement measuring line 145 connected to the source line 130, the drain 105, and the displacement connected to the source line 130, the drain 105, and formed on the active matrix 100 having M × N transistors embedded therein. A first metal layer 150 including a measurement pad 140; An actuator (230) formed on the first metal layer (150) and the active matrix (100) and including a support layer (180), a lower electrode (185), a strain layer (190), and an upper electrode (195); A displacement measuring member (199) formed on the actuator (230) and including a piezoelectric layer (196) for measuring displacement and an upper displacement measuring line (198); A first via contact 215 connecting the lower electrode 185 and the drain pad 135 to each other; A second via contact 220 connecting the upper displacement measuring line 198 and the displacement measuring pad 140 to each other; And Thin film type optical path control device comprising a mirror (200) formed on the support layer (180). The piezoelectric layer 196 of claim 1, wherein the piezoelectric layer 196 for displacement measurement is formed using PZT or PLZT, and the upper displacement measurement line 198 is formed using platinum, tantalum, platinum-tantalum, aluminum, or silver. Thin film type optical path control device, characterized in that. Stacking and patterning a first metal layer on an active matrix including M × N transistors to form a source line, a drain pad connected to a drain, and a lower displacement measuring line and a displacement measuring pad connected thereto; Forming an actuator on the first metal layer and the active matrix, the actuator including a support layer, a lower electrode, a strain layer, and an upper electrode; Forming a displacement measuring member including a piezoelectric layer for displacement measurement and an upper displacement measurement line on an upper portion of the actuator; Forming a first via contact connecting the lower electrode and the drain pad; Forming a second via contact connecting the upper displacement measuring line and the displacement measuring pad; And Method of manufacturing a thin film type optical path control device comprising the step of forming a mirror on top of the support layer. The method of claim 3, wherein the forming of the first via contact and the forming of the second via contact are performed simultaneously.

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