KR100251109B1 - Thin film actuated mirror array and manufacturing method of the same - Google Patents

Abstract

PURPOSE: A thin-film micromirror array-actuated(TMA) and a manufacturing method thereof are provided to adhere an AMA element-formed active matrix in the upper potion of a flat plate, thereby correcting the bow of an active matrix. CONSTITUTION: A flat plate(230) with plural holes(240) and protrusions(235) is adhered to the back of an active matrix with a bow by using an epoxy. A pump extracts an air through the plurality of holes(240) formed in the surface of the flat plate(230) for about 1 hour. A lamp heats the flat plate(230) in the temperature of 60 to 80 deg.C to accelerate the curing of the epoxy. The plural protrusions(235) maintains the gap between the back of the active matrix and the flat plate(230) so that the air is easily extracted through the plural holes(240) of the flat plate(230). Therefore, the AMA element-formed active matrix is evenly adhered to the upper of the flat plate and the bow of the active matrix is corrected.

Description

Thin film type optical path control device and its manufacturing method

The present invention relates to a thin film type optical path control device using AMA (Actuated Mirror Array) and a method of manufacturing the same, and more particularly, to a thin film type optical path control device that can realize a uniform image by correcting the bow (bow) of the active matrix and It relates to a manufacturing method.

Optical path control devices or spatial light modulators for projecting optical energy onto a screen may be applied to various fields such as optical communication, image processing, and information display devices. Typically, such devices are classified into a direct-view image display device and a projection-type image display device according to a method of displaying optical energy on a screen.

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. In the AMA, each of the mirrors installed therein reflects light incident from the light source at a predetermined angle, and the reflected light is projected on the screen through an aperture such as a slit or a pinhole. It is a device that can adjust the speed of light to form an image. Therefore, its structure and operation principle are simple, and high light efficiency (more than 10% light efficiency) can be obtained compared to LCD or DMD. In addition, contrast can be improved to obtain a bright and clear 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 thereon is tilted. Accordingly, the inclined mirrors reflect light incident from the light source at a predetermined angle to form an image on the screen. Piezoelectric materials such as PZT (Pb (Zr, Ti) O ₃ ), or PLZT ((Pb, La) (Zr, Ti) O ₃ ) are used as actuators for driving the respective mirrors. The actuator may also be configured as a warping material such as PMN (Pb (Mg, Nb) O ₃ ).

These AMA devices are largely divided into bulk type and thin film type. The bulk optical path control device is 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 it 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. The thin film type optical path control device is disclosed in Korean Patent Application No. 96-42197 (name of the invention: a method of manufacturing a thin film type optical path control device that can control the stress of the membrane) filed by the applicant of the Korean Patent Office on September 24, 1996. It is.

Figure 1 shows a cross-sectional view of the thin film type optical path control device described in the preceding application.

Referring to FIG. 1, the thin film type optical path adjusting device includes an active matrix 1 and an actuator 60. An active matrix 1 having M × N (M, N is an integer) MOS transistors and a drain pad 5 formed on one surface thereof includes the active matrix 1 and The protective layer 10 may be stacked on the drain pad 5, and the etch stop layer 15 may be stacked on the protective layer 10.

The actuator 60 may be stacked such that one side of the actuator 60 is in contact with a portion of the etch stop layer 15 in which the drain pad 5 is formed, and the other side thereof is parallel to the etch stop layer 15 via the air gap 25. Membrane 30, lower electrode 35 stacked on top of membrane 30, strained layer 40 stacked on top of lower electrode 35, and stacked on top of strained layer 40. Vias formed vertically from the one side of the upper electrode 45 and 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 50 includes a via contact 55 formed in the via hole 50 such that the lower electrode 35 and the drain pad 5 are electrically connected to each other.

A stripe 46 is formed on a portion of the upper electrode 45. The stripe 46 operates the upper electrode 45 uniformly to prevent diffuse reflection of light incident from the light source.

Hereinafter, the manufacturing method of the said thin film type optical path control apparatus is demonstrated.

First, an silicate is formed on an n-type doped silicon wafer and contains an M x N (M, N is an integer) P-MOS transistor embedded therein and an insilicate on an active matrix 1 having a drain pad 5 formed thereon. 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 from subsequent processes.

An etch stop layer 15 made of nitride is formed on the protective layer 10. The etch stop layer 15 is formed to have a thickness of about 0.01 to 1.0 탆 using a low pressure chemical vapor deposition (LPCVD) method. The etch stop layer 15 prevents the protective layer 19 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 such that PSG having a high concentration of phosphorus (P) has a thickness of about 1.0 to 3.0 μm 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. Therefore, 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 to form a support part of the actuator.

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

The lower electrode 35 made of a metal such as platinum (Pt) or platinum-tantalum (Pt-Ta) is formed on the membrane 30. The lower electrode 35 is formed to have a thickness of about 0.01 to 1.0 µm using a sputtering method. Subsequently, the lower electrode 35 is patterned into a predetermined pixel shape by using a reactive ion etching process using an etching end point so that an independent first signal (image signal) is applied to each pixel (Iso-cutting process).

The strain layer 40 formed of PZT is formed on the lower electrode 35. The strained layer 40 is spin-coated to have a thickness of about 0. 1 to 1.0 μm, preferably about 0.4 μm using a sol-gel method. Phase change is achieved by rapid thermal annealing (RTA). The strained layer 40 is deformed by an electric field generated between the upper electrode 45 and the lower electrode 35.

The upper electrode 45 is formed on the strained layer 40. The upper electrode 45 is formed of a metal having excellent electrical conductivity and reflectivity, such as aluminum or platinum, to have a thickness of about 0.01 to 1.0 탆 using a sputtering method. The second signal (bias signal) is applied to the upper electrode 45 from the outside through a common electrode line (not shown). In addition, the upper electrode 45 also functions as a mirror that reflects light incident from the light source.

Subsequently, the strained layer 40, the lower electrode 35, the membrane 30, the etch stop layer 15, and the protective layer 10 are disposed from one upper portion of the strained layer 40 to an upper portion of the drain pad 5. The via holes 50 are formed by sequentially etching. Subsequently, a metal such as tungsten, platinum or titanium is deposited by a lift-off method to form a via contact 55 that electrically connects the drain pad 5 and the lower electrode 35. Therefore, the via contact 55 is formed vertically from the lower electrode 35 to the top of the drain pad 5 in the via hole 50. Therefore, the first signal (image signal) applied from the outside is applied to the lower electrode 10 through the transistor, the drain pad 5 and the via contact 55 built in the active matrix 1.

Subsequently, the upper electrode 45 is patterned into a predetermined pixel shape. In this case, the stripe 46 is patterned so that the stripe 46 is formed on one side of the upper electrode 45. Subsequently, the strained layer 40 and the lower electrode 35 are sequentially patterned into a predetermined pixel shape.

Subsequently, a photoresist layer (not shown) is applied to the entire surface of the resultant in which the via contact 55 is formed and patterned to expose the membrane 30. Subsequently, the membrane 30 is anisotropically etched using the photoresist layer as an etching mask, thereby patterning a predetermined pixel shape. Subsequently, after forming the air gap 59 by isotropically etching the sacrificial layer 20 by 49% hydrogen fluoride (HF) vapor using the photoresist layer as an etching mask, rinsing and drying are performed. To complete the AMA device.

In the above-described thin film type optical path adjusting device, the first signal is applied to the lower electrode 35 which is a signal electrode through the drain pad 5 and the via contact 55 from the MOS transistor embedded in the active matrix 1. In addition, 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. Due to this 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 electric field, and the actuator 60 including the strained layer 40 is bent in a direction opposite to the direction in which the membrane 30 is formed. 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, according to the above-described thin film type optical path adjusting device, bows are formed by bending both ends of the active matrix 1 in which the AMA panel is formed. Since the bow operates in the same way as the initial tilting angle (tilting angle) in the actuator pixel, there arises a problem that the screen brightness at both ends is different on the screen.

Accordingly, the present applicant has developed a thin film type optical path control device capable of correcting the bow of the active matrix, which is a patent application No. 97-21955 filed with the Korean Intellectual Property Office on May 30, 1997. : Thin-film optical path control device and its manufacturing method).

Figure 2 shows a cross-sectional view of the thin film type optical path control device described in the preceding application.

Referring to FIG. 2, the thin film type optical path adjusting device includes an active matrix 70 and an actuator 90 formed on the active matrix 70.

The active matrix 70 made of an n-type silicon wafer and containing M × N P-MOS transistors includes a first metal layer 72 stacked on top of it and a first protective layer stacked on top of the first metal layer. 74, a second metal layer 76 stacked on top of the first passivation layer, a second passivation layer 78 stacked on top of the second metal layer, and an etching layer stacked on top of the second passivation layer. The prevention layer 80 is included.

The first metal layer 72 includes a drain pad for transmitting a first signal. The second metal layer 76 includes a first layer 76a made of titanium (Ti) and a second layer 76b made of titanium nitride (TiN).

The actuator 90 has a support layer 82 stacked in parallel with the etch stop layer 80 through one side of the etch stop layer 80, the one side of which is in contact with a portion where the drain pad is formed, and the other side via the air gap 95. Lower electrode 84 stacked on top of support layer 82, strain layer 86 stacked on top of lower electrode 84, upper electrode 88 stacked on top of strain layer 86, and the strain From one side of the layer 86 through the upper strain deformation layer 86, the lower electrode 84, the support layer 82, the etch stop layer 80, the second protective layer 78, and the first protective layer 74 And a via contact 96 formed in the via hole 94 vertically up to the drain pad.

Moreover, the metal plate 98 is adhere | attached by the conductive adhesive 97 on the back surface of the active matrix 70 in which AMA panel is formed. A plurality of holes 99 are drilled in the surface of the metal plate 98 as shown in FIG. 3. Thus, a vacuum chuck is used to extract air from the holes 99 of the metal plate 98 before the conductive adhesive 97 solidifies, thereby applying a force to the metal plate 98. The active matrix 70 on which the AMA panel is formed is adhered flatly. As a result, the bow of the active matrix 70 is corrected.

However, according to the above-described thin film type optical path adjusting device, since the active matrix and the metal plate are tightly adhered to each other, it is difficult to substantially extract air from the holes of the metal plate.

Accordingly, an object of the present invention is to provide a thin film type optical path control apparatus and a method of manufacturing the same, which can realize a uniform image by correcting a bow of an active matrix.

1 is a cross-sectional view of a thin film type optical path adjusting device described in the applicant's prior application.

2 is a cross-sectional view of a thin film type optical path adjusting device described in another prior application of the applicant.

3 is a plan view of the metal plate shown in FIG. 2.

4 is a plan view of a 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 A′A ′.

FIG. 6 is a plan view of the plate illustrated in FIG. 5. FIG.

FIG. 7 is a cross-sectional view of the plate illustrated in FIG. 6 taken along line B′B ′. FIG.

8A to 8F are cross-sectional views illustrating a method of manufacturing the device shown in FIG. 5.

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

100: active matrix 155: first metal layer

160: first protective layer 165: second metal layer

170: second protective layer 175: etch stop layer

180: sacrificial layer 185: support layer

190: lower electrode 195: strained layer

200: upper electrode 205: actuator

210: beer hall 215: beer contact

220: stripe 225: air gap

230: flat plate 235: protrusion

240: hole

In order to achieve the above object, the present invention provides an active matrix including an M × N (M, N is an integer) MOS transistor and including a first metal layer, an actuator formed on the active matrix, and an active matrix. Provided is a thin film type optical path control apparatus including a flat plate adhered to a rear surface and having a plurality of protrusions and a plurality of holes formed thereon.

The actuator may include: i) a support layer on one side of which is in contact with the top of the active matrix and the other side of the actuator being formed parallel to the active matrix via an air gap; ii) a bottom electrode formed on the top of the support layer; And a strained layer formed on the strained layer, and iii) an upper electrode formed on the strained layer.

In addition, to achieve the above object, the present invention comprises the steps of providing an active matrix containing M × N (M, N is an integer) MOS transistor and comprises a first metal layer; I) forming a support layer on top of the active matrix, i) forming a support layer in parallel with the active matrix with one side contacting the top of the active matrix and the other side via an air gap, ii) forming a lower electrode on the support layer (Iii) forming an actuator on top of the lower electrode, and iii) forming an upper electrode on top of the strained layer; And attaching a flat plate having a plurality of protrusions and a plurality of holes formed on the surface thereof to the back surface of the active matrix.

According to the thin film type optical path control device according to the present invention, a flat plate is bonded to the back surface of an active matrix having an bow by forming an AMA element thereon using a thermosetting resin (epoxy). The plate has a plurality of holes formed on the surface thereof, and a plurality of protrusions are formed on the surface thereof so that air can be drawn out using a pump. After bonding the active matrix on which the AMA element is formed and the plate with a thermosetting resin, the plate is heated by drawing air from the holes of the plate through a pump connected to the back surface of the plate to heat the plate. Promotes curing. At this time, since a predetermined gap is maintained between the back surface of the active matrix and the flat plate by the protrusion of the flat plate, air can be easily extracted from the holes of the flat plate.

Therefore, the active matrix having the AMA element formed thereon is flatly adhered to the upper portion of the flat plate, thereby correcting the bow.

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

Figure 4 shows a plan view of the thin film type optical path control apparatus according to the present invention, Figure 5 shows a cross-sectional view taken along the line AA 'of the apparatus shown in FIG.

4 and 5, the thin film type optical path control apparatus of the present invention includes an active matrix 100 and an actuator 205 formed on the active matrix 100.

The active matrix 100 is preferably made of an n-type silicon wafer and has M × N (M, N is an integer) P-MOS transistors having a gate 115, a source 110, and a drain 105. It is built. In addition, the active matrix 100 may include a first metal layer 155 stacked on the active matrix 100, a first passivation layer 160 stacked on the first metal layer 155, and a first passivation layer ( The second metal layer 165 stacked on the upper portion of the 160, the second protective layer 170 stacked on the second metal layer 165, and the etch stop layer 175 stacked on the second protective layer 170. It includes. Here, reference numeral 120 denotes an isolation layer for dividing the active matrix 100 into an active region and a field region, and reference numeral 125 denotes a first metal layer 155 in which the gate 115 of the P-MOS transistor is stacked thereon. The insulating film for insulating from is shown.

The first metal layer 155 includes a drain pad extending from the drain region of the transistor to transmit a first signal (image signal), and the second metal layer 165 is a first layer made of titanium (Ti). 165a and a second layer 165b made of titanium nitride (TiN).

One side of the actuator 205 is in contact with a portion of the etch stop layer 175 where the drain pad of the first metal layer 155 is formed, and the other side is parallel to the etch stop layer 175 through the air gap 225. The support layer 185 stacked above, the lower electrode 190 stacked on top of the support layer 185, the strain layer 195 stacked on top of the lower electrode 190, and the top layer stacked on top of the strain layer 195. The electrode 200 and the strained layer 195, the lower electrode 190, the support layer 185, the etch stop layer 175, the second passivation layer 170, and the first protection from one side of the strained layer 195. And a via contact 215 formed in the via hole 210 formed vertically through the layer 160 to the drain pad.

In addition, referring to FIG. 4, one side of the plane of the support layer 185 has a concave portion having a rectangular shape at its center, and the concave portion is formed in a shape that is stepped toward both edges. The other side of the plane of the support layer 185 has a rectangular protrusion that narrows stepwise toward the central portion corresponding to the concave portion. Therefore, the protruding portion of the support layer of the actuator adjacent to the concave portion of the support layer 185 is fitted, and the rectangular projection is fitted into the concave portion of the adjacent support layer. The support layer 185 functions as a membrane supporting the actuator of the thin film type optical path adjusting device described in the previous application. A stripe 220 is formed at the center of the upper electrode 200 to uniformly operate the upper electrode 200 to prevent diffuse reflection of the incident light beam.

Referring to FIG. 5, the flat plate 230 is bonded to the back surface of the active matrix 100 on which the AMA panel is formed by a thermosetting resin. FIG. 6 is a plan view of the plate 230, and FIG. 7 is a cross-sectional view of the plate 230 taken along line B′B ′.

6 and 7, a plurality of protrusions 235 and a plurality of holes 240 are formed on the surface of the flat plate 230. The protrusions 235 are arranged to bond the back surface of the active matrix 100 to the flat plate 230 while maintaining a predetermined gap, and to uniformly support the active matrix 100. The holes 240 are formed to extract air, and extract air from the holes 240 through a pump connected to the rear surface of the flat plate 230.

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.

8A to 8F are cross-sectional views for explaining the method for manufacturing the device shown in FIG. 5. 8A to 8F, the same reference numerals are used for the same members as in FIG.

Referring to FIG. 8A, after preparing an active matrix 100 formed of, for example, an n-type doped silicon substrate, the active matrix (eg, a local oxidation of silicon (LOCOS)) may be manufactured using a conventional device isolation process, for example, a local oxidation of silicon (LOCOS) method. An isolation layer 120 is formed in 100 to separate the active region and the field region. Subsequently, a gate 115 made of a conductive material such as polysilicon doped with impurities is formed on the active region, and then p ⁺ source 110 and drain 105 are formed by an ion implantation process. N (M, N is an integer) P-MOS transistors are formed.

Subsequently, after forming the first insulating layer 125 made of an oxide on the P-MOS transistor formed product, the first metal layer 155 is formed thereon and patterned by a photolithography process. The first metal layer 155 is made of tungsten (W) and includes a drain pad extending to one side of the support layer 185 formed in a subsequent process.

Referring to FIG. 8B, a first protective layer 160 is formed on the first metal layer 155 to protect the active matrix 100 having the P-MOS transistor. The first passivation layer 160 is formed to have a thickness of about 8000 GPa by using a vapor deposition method (CVD) of phosphorus silicate glass (PSG). The first protective layer 160 prevents the transistor embedded in the active matrix 100 from being damaged during subsequent processes.

The second metal layer 165 is formed on the first passivation layer 160. In order to form the second metal layer 165, first, a first layer 165a having a thickness of about 300 μs is formed by sputtering titanium. Next, titanium nitride is deposited on the first layer 165a by using a physical vapor deposition (PVD) method to form a second layer 165b. Since the second metal layer 165 is incident on not only the upper electrode 200 of which the luminous flux incident from the light source is the reflective layer but also a portion other than the portion where the upper electrode 200 is formed, a light leakage current is generated in the active matrix 100. To prevent the device from malfunctioning. Subsequently, a portion of the second metal layer 165 where the via contact 215 is to be formed in a subsequent process is etched through a photolithography process.

Subsequently, a second protective layer 170 is formed on the second metal layer 165. The second protective layer 170 is formed to a thickness of about 2000 kPa using in-silicate glass (PSG). The second protective layer 170 also prevents damage to the transistor embedded in the active matrix 100 during the subsequent process.

Subsequently, an etch stop layer 175 is formed on the second passivation layer 170. The etch stop layer 175 prevents the active matrix 100 and the second passivation layer 170 from being etched due to the subsequent etching process. The etch stop layer 175 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 ~ 2000Å.

Subsequently, a sacrificial layer 180 is formed on the etch stop layer 175. The sacrificial layer 180 is formed by depositing a phosphorus silicate glass (PSG) to a thickness of about 2.0 to 3.2㎛ using the atmospheric pressure chemical vapor deposition (APCVD) method. In this case, since the sacrificial layer 180 covers the top of the active matrix 100 in which the transistor is embedded, the surface flatness is very poor. Accordingly, the surface of the sacrificial layer 180 is polished so that the sacrificial layer 180 has a thickness of about 1 μm by using spin on glass (SOG) or chemical mechanical polishing (CMP). By planarizing it. Subsequently, a portion of the planarization sacrificial layer 180 where the drain pad of the first metal layer 155 is formed is etched to expose a portion of the etch stop layer 175, thereby forming a support of the actuator 205.

Referring to FIG. 8C, the support layer 185 is formed on the exposed etch stop layer 175 and on the sacrificial layer 180. The support layer 185 is formed to have a thickness of about 1000 to 3000 GPa using a low pressure chemical vapor deposition (LPCVD) method.

Subsequently, a lower electrode 190 is formed on the support layer 185. The lower electrode 190 is formed to have a thickness of about 2000 to 4000 microns by sputtering a metal such as platinum (Pt), tantalum (Ta), or platinum-tantalum (Pt-Ta). At the same time, the lower electrode 190 is separated for each pixel so that an independent first signal (image signal) is applied to each pixel (Iso-cutting process). The first signal transferred from the transistor embedded in the active matrix 100 is applied to the lower electrode 190.

Subsequently, a strained layer 195 formed of a piezoelectric material such as PZT or PLZT is formed on the lower electrode 190. The strained layer 195 is formed to have a thickness of about 4000 to 6000 kPa, preferably about 4000 kPa using a sol-gel method, a sputtering method, or a chemical vapor deposition method. In addition, the piezoelectric material constituting the strained layer 195 is subjected to heat treatment by a rapid heat treatment (RTA) method to perform phase shift. The strained layer 195 is deformed by an electric field generated between the upper electrode 200 and the lower electrode 190.

Subsequently, an upper electrode 200 is formed on the strained layer 195. The upper electrode 200 is formed to have a thickness of about 2000 to 6000 microns by sputtering a metal such as aluminum (Al), silver (Ag), or platinum (Pt). The upper electrode 200 is applied with a second signal (bias signal) from the outside through a common electrode line (not shown). Since the upper electrode 200 has excellent electrical conductivity and reflectivity, the upper electrode 200 performs not only a function of a bias electrode generating an electric field but also a function of a mirror reflecting light incident from a light source.

Subsequently, the upper electrode 200, the deformation layer 195, the lower electrode 190, and the support layer 185 are sequentially etched and patterned from an upper portion of the upper electrode 200. In this case, a stripe 220 is formed at the center of the upper electrode 200 to uniformly operate the upper electrode 200 to prevent diffuse reflection of the light beam incident from the light source.

Referring to FIG. 8D, the strained layer 195, the lower electrode 190, the support layer 185, the etch stop layer 175, the second passivation layer 170, and the first protection from one side of the strained layer 195. The layers 160 are sequentially etched to form via holes 210. Accordingly, the via hole 210 is formed from one side of the strained layer 195 to the drain pad of the first metal layer 155. Subsequently, a metal having excellent electrical conductivity such as tungsten (W), aluminum (Al), or titanium (Ti) is deposited using a sputtering method to form a via contact 215. The via contact 215 electrically connects the drain pad of the first metal layer 155 and the lower electrode 190. Therefore, the first signal applied from the outside is applied to the lower electrode 190 through the transistor, the drain pad, and the via contact 215 embedded in the active matrix 100.

Referring to FIG. 8E, the sacrificial layer 180 is etched using hydrogen fluoride (HF) vapor to form an air gap 225, and then cleaned and dried to complete an AMA device.

Referring to FIG. 8F, the active matrix 100 in which the AMA panel is formed is cut into a predetermined shape as described above. Subsequently, after preparing a flat plate 230 having a plurality of protrusions 235 and a plurality of holes 240 formed on the surface thereof, a thermosetting resin is lightly applied to the upper surface of the flat plate 230. After about 10 minutes, the cut active matrix 100 is placed on top of the flat plate 230.

Subsequently, air is extracted from the holes 240 of the plate 230 for about 1 hour using a pump (not shown) connected to the rear surface of the plate 230, and at the same time a lamp (not shown) Curing the thermosetting resin by heating the flat plate 230 to a temperature of about 60 to 80 ° C. As a result, the back surface of the active matrix 100 on which the AMA panel is formed is adhered to the flat plate 230 in a flat manner so that the bow generated in the active matrix 100 is corrected.

When the active matrix 100 is completely fixed to the flat plate 230 by the above method, 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 from the outside is the lower electrode through the transistor embedded in the active matrix 100, the drain pad of the first metal layer 155 and the via contact 215. Is applied to 190. At the same time, a second signal is applied to the upper electrode 200 from the outside through a common electrode line, thereby generating an electric field between the upper electrode 200 and the lower electrode 190. Due to this electric field, the deformation layer 195 formed between the upper electrode 200 and the lower electrode 190 causes deformation. The strained layer 195 contracts in a direction orthogonal to the electric field, and thus the actuator 205 is bent at a predetermined angle. The upper electrode 200, which also functions as a mirror that reflects light, is formed on the actuator 205 and is inclined together with the actuator 205. Accordingly, the upper electrode 200 reflects the light incident from the light source at a predetermined angle, and the reflected light passes through the slit to form an image on the screen.

As described above, according to the thin film type optical path adjusting device and the manufacturing method thereof, the flat plate is bonded to the back surface of the active matrix having a bow by forming an AMA element thereon using a thermosetting resin. The plate has a plurality of holes formed on the surface thereof, and a plurality of protrusions are formed on the surface thereof so that air can be drawn out using a pump. After bonding the active matrix on which the AMA element is formed and the plate with a thermosetting resin, the plate is heated by extracting air from the holes of the plate through a pump connected to the rear surface of the plate to heat the plate. Promotes curing. In this case, since a predetermined gap is maintained between the back surface of the active matrix and the flat plate by the protrusion of the flat plate, air can be easily extracted from the holes of the flat plate to completely adhere the flat plate to the active matrix.

Therefore, the active matrix on which the AMA element is formed is flatly adhered to the upper portion of the flat plate, thereby correcting the bow of the active matrix.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

Claims (9)

An active matrix 100 including M × N (M, N is an integer) transistors and including a first metal layer 155; I) a support layer 185 formed on the active matrix 100 in parallel with the active matrix 100 with one side contacting the upper side of the active matrix 100 and the other side via the air gap 225, ii A lower electrode 190 formed on the support layer 185, iii) a strained layer 195 formed on the lower electrode 190, and iii) an upper electrode formed on the strained layer 195. Actuator 205 with 200; And The thin film type optical path control device is adhered to the back surface of the active matrix (100) and includes a flat plate (230) having a plurality of protrusions (235) and a plurality of holes (240) formed on the surface. The apparatus of claim 1, wherein the flat plate is bonded to the back surface of the active matrix by a thermosetting resin. The apparatus of claim 1, wherein a predetermined gap is formed between the active matrix (100) and the plate (230) by the protrusions (235) of the plate (230). The method of claim 1, wherein the active matrix 100 includes a first passivation layer 160 formed on the first metal layer 155 and a second metal layer 165 formed on the first passivation layer 160. ), A second passivation layer 170 formed on the second metal layer 165, and an etch stop layer 175 formed on the second passivation layer 170. Device. The method of claim 1, wherein the actuator 205 is vertically formed from one side of the deformable layer 195 to the first metal layer 155 to electrically connect the lower electrode 190 and the first metal layer 155. Thin film type optical path control device further comprises a via contact (215) for connecting. Providing an active matrix including M × N (M, N is an integer) transistors and including a first metal layer; I) forming a support layer on top of the active matrix, i) forming a support layer in parallel with the active matrix with one side contacting the top of the active matrix and the other side via an air gap, ii) forming a lower electrode on the support layer (Iii) forming an actuator on top of the lower electrode, and iii) forming an upper electrode on top of the strained layer; And A method of manufacturing a thin film type optical path control device comprising the step of adhering a flat plate having a plurality of protrusions and a plurality of holes formed on the surface thereof to the back surface of the active matrix. The method of manufacturing a thin film type optical path control device according to claim 6, wherein the step of adhering the flat plate to the back surface of the active matrix is performed after cutting the active matrix into a predetermined shape. The method of claim 6, wherein the bonding of the flat plate to the back surface of the active matrix comprises bonding the flat plate having a plurality of protrusions and a plurality of holes to the back surface of the active matrix using a thermosetting resin. And extracting air from the holes of the flat plate by using a pump connected to the back surface of the flat plate. The method of claim 8, wherein the extracting air from the holes of the plate comprises heating the plate to promote hardening of the thermosetting resin.

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