KR100251114B1 - Manufacturing method of ama - Google Patents

Abstract

PURPOSE: A method for manufacturing a thin film type optical path adjusting device is provided to prevent a supporting layer of a lower electrode from being damaged by not performing an over-etching in an 'Iso-cut' etching process. CONSTITUTION: A lower electrode is formed with depositing the first conductive layer(130a) on a supporting layer(125) and depositing the second conductive layer(130b) on the first conductive layer(130a). A photoresist layer(131) is formed on the lower electrode(130). An oxygen ion injection and a heat treatment are performed using the photoresist layer(131) as an ion injection mask. As a result, the lower electrode(130) is short-circuited for each pixel. A strain layer is formed on the short-circuited lower electrode(130). An upper electrode is formed on the strain layer.

Description

Manufacturing method of thin film type optical path control device

The present invention relates to a method of manufacturing a thin film type optical path control device using an Actuated Mirror Array (AMA), and more particularly, to a method of manufacturing a thin film type optical path adjusting device formed at a lower portion thereof when an etching process for shorting a lower electrode for each pixel is performed. The present invention relates to a method for manufacturing a thin film type optical path control device capable of preventing an attack of a support layer.

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. The image processing apparatus using the optical path adjusting device or the 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. Projection type image display devices 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% and requires 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 (10% or more) 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 image signal and the bias voltage. As the actuator deforms, each of the mirrors mounted thereon is tilted. Accordingly, the inclined mirrors reflect the incident light 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 can 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 adjusting device is made by thinly cutting a multilayer ceramic to mount a ceramic wafer having a metal electrode formed therein in an active matrix in which a transistor is embedded, and then processing by a sawing method and installing a mirror thereon. 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 the 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) that the applicant filed a patent with the Korean Patent Office on September 24, 1996 It is.

1 is a cross-sectional view of a thin film type optical path adjusting device described in the above prior 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 side thereof includes the active matrix 1 and A passivation layer 10 stacked on top of the drain pad 5 and an etch stop layer 15 stacked on top of the passivation layer 10 are included.

The actuator 60 is a membrane in which one side is in contact with a portion of the etch stop layer 15 in which the drain pad 5 is formed and the other side is parallel to the active matrix 1 via the air gap 25. 30, a lower electrode 35 stacked on the membrane 30, a strained layer 40 stacked on the lower electrode 35, and an upper electrode stacked on the strained layer 40. 45, a via hole vertically formed 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 lower electrode 35 and the drain pad 5 are formed in the via contact 55 to be 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, a method of manufacturing the thin film type optical path control device will be described with reference to FIGS. 2A to 2D.

Referring to FIG. 2A, a phosphorus-silicate glass (phosphor—) is formed on an active matrix 1 having M × N (M and N are integers) transistors (not shown) and a drain pad 5 formed on one side thereof. A protective layer 10 made of silicate glass (PSG) is formed. The protective layer 10 is formed to have a thickness of about 1.0 μm using chemical vapor deposition (CVD). 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 may be formed to have a thickness of about 0.1 μm to about 1.0 μm 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 a PSG having a high concentration of phosphorus (P) to have a thickness of about 1.0 μm 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 to form a position where the support portion of the actuator is to be formed.

Referring to FIG. 2B, the membrane 30 is formed on the exposed etch stop layer 15 and the sacrificial layer 20 to a thickness of about 0.1 μm to about 1.0 μm. 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.

On the membrane 30, for example, a lower electrode 35 made of platinum (Pt) -tantalum (Ta) is formed. Subsequently, the lower electrode 35 is etched to short the lower electrode 35 for each pixel so that an independent first signal (image signal) is applied to each pixel (Iso-cut etching process).

The deformation layer 40 formed of PZT or PLZT is formed on the lower electrode 35. 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 a phase change is performed by a rapid thermal annealing (RTA) method. Makes it. The deformation layer 40 is deformed by an electric field generated between the upper electrode 45 that is a common electrode and the lower electrode 35 that is a signal electrode.

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 so as to have a thickness of about 0.1 to 1.0 μm using a sputtering method. The second signal (bias signal) is applied to the upper electrode 45 which is the common electrode. In addition, the upper electrode 45 also functions as a mirror that reflects light incident from the light source.

Referring to FIG. 2C, 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, and then the strained layer 40 is formed from an upper portion of one side of the strained layer 40 to an upper portion of the drain pad 5. The via hole 50 is formed by sequentially etching the lower electrode 35, the membrane 30, the etch stop layer 15, and the protective layer 10. 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 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.

Referring to FIG. 2D, a photoresist layer (not shown) is coated on the entire surface of the resultant product 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, the air gap 25 is formed by isotropically etching the sacrificial layer 20 by 49% hydrogen fluoride (HF) vapor using the photoresist layer as an etching mask. Subsequently, the AMA device is completed by removing the photoresist layer and performing a cleaning and drying process to remove the remaining etching solution.

In the above-described thin film type optical path adjusting device, an image signal current is applied to the lower electrode 35 which is a signal electrode through the MOS transistor, the drain pad 5, and the via contact 55 embedded in the active matrix 1. In addition, a second signal is applied to the upper electrode 45 through a common electrode line (not shown) from the outside 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, in the above-described thin film type optical path control apparatus, when the “Iso-cut” etching process for shorting the lower electrode for each pixel is performed, the etching of the etching equipment is performed to perform a complete “Iso-cut” etching in the entire thin film type AMA module. Uniformity must be compensated for. Therefore, the etching process must proceed with over etching. In this case, the membrane, which is the lower layer of the lower electrode, is etched together, resulting in a failure of the thin film type AMA device after completion of the process.

3 is a plan view of a thin film type optical path control apparatus after the above-mentioned "Iso-cut" etching process.

As shown in FIG. 3, when the photolithography process for patterning the deformed layer 40 and the lower electrode 35 into a pixel shape after completing the “iso-cut” etching process, the “A” portion is a photo. It is continuously etched because it is opened without being covered by the resist. Thus, the membrane 30 in the "A" part is etched continuously, which causes damage and causes process failure.

Accordingly, it is an object of the present invention to provide a method for manufacturing a thin film type optical path control apparatus capable of preventing damage to a support layer under the Iso-cut etching process for shorting a lower electrode for each pixel.

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

2A to 2D are cross-sectional views illustrating a method of manufacturing the apparatus shown in FIG. 1.

3 is a plan view of a thin film type optical path control apparatus after an etching process for shorting the lower electrode of FIG. 2B for each pixel.

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 B′B ′.

6A to 6F are cross-sectional views illustrating a method of manufacturing the apparatus shown in FIG. 5.

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

100: active matrix 200: actuator

105: drain pad 110: protective layer

115: etch stop layer 125: support layer

130: lower electrode 135: strained layer

140: upper electrode 145: via hole

150: beer contact

In order to achieve the above object of the present invention, the present invention comprises the steps of providing an active matrix having a drain pad formed on one side thereof; And forming a support layer on top of the active matrix, i) one side of which is in contact with the top of the active matrix and the other side parallel to the active matrix via an air gap, ii) a first conductive layer on top of the support layer. And forming a lower electrode by laminating a second conductive layer, iii) exposing the first conductive layer of the lower electrode by performing oxygen (O ₂ ) ion implantation after etching the second conductive layer of the lower electrode. Shorting the lower electrode by each pixel by making a part an insulator, iii) forming a strained layer on top of the lower electrode, and v) forming an upper electrode on top of the strained layer. It provides a method for manufacturing a thin film type optical path control device comprising the step of forming.

In the above-described thin film type optical path control device of the present invention, the first signal transmitted from the outside through the pad of the TCP and the pad of the AMA panel is a lower electrode which is a signal electrode through the MOS transistor, the drain pad, and the via contact embedded in the active matrix. Is applied to. At the same time, a second signal is applied to the upper electrode through the common electrode line from the outside to generate an electric field between the upper electrode and the lower electrode. By this electric field, the strained layer laminated between the upper electrode and the lower electrode causes deformation. The strained layer contracts in a direction perpendicular to the electric field, and the actuator including the strained layer is bent upward at a predetermined angle. Therefore, the upper electrode which also functions as a mirror on the actuator is inclined in the same direction. Accordingly, the light incident from the light source is reflected by the inclined upper electrode at a predetermined angle, and then passes through the slit to be projected onto the screen to form an image.

As described above, according to the manufacturing method of the thin film type optical path control apparatus according to the present invention, a lower electrode formed by stacking a first conductive layer, such as tantalum (Ta) and a second conductive layer, such as platinum (Pt), is short-circuited for each pixel. In the “Iso-cut” etching process, the second conductive layer of the lower electrode is etched by an etching process using an etching end point (EOP), and then oxygen ion implantation is performed on the exposed surface. . As a result, the first conductive layer becomes an insulator such as an insulator of tantalum-oxygen (Ta-O), so that the lower electrode is shorted for each pixel.

Therefore, since the present invention does not perform excessive etching during the “Iso-cut” etching process, the lower electrode can be shorted for each pixel while preventing damage to the lower layer (support layer) of the lower electrode due to over etching.

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

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

4 and 5, the thin film type optical path adjusting apparatus according to the present invention includes an active matrix 100 and an actuator 200 formed on the active matrix 100. An active matrix 100 having M × N (M, N is an integer) MOS transistors and a drain pad 105 formed on one side thereof has an upper portion of the active matrix 100 and the drain pad 105. The protective layer 110 is stacked on the protective layer 110, and the anti-etching layer 115 stacked on top of the protective layer 110.

The actuator 200 is in contact with a portion of the etch stop layer 115 in which the drain pad 105 is formed, and the other side thereof is parallel to the active matrix 100 via an air gap (not shown). The support layer 125 having a stacked cross section, the lower electrode 130 stacked on the support layer 125, the strained layer 135 stacked on the upper portion of the lower electrode 130, and the strained layer 135 From one side of the upper electrode 140, the deformation layer 135 stacked on the upper electrode 130, the support layer 125, the etch stop layer 115 and the protective layer 110 through the drain pad 105 A via contact 155 is formed in the via hole 145 vertically formed so that the lower electrode 130 and the drain pad 105 are electrically connected to each other.

In addition, referring to FIG. 4, the plane of the support layer 125 is formed in a shape in which one side thereof has a rectangular concave portion at a central portion thereof, and the concave portion widens stepwise toward both edges. The other side of the plane of the support layer 125 has a quadrangular protrusion that narrows stepwise toward the central portion corresponding to the concave portion. Therefore, the protrusion of the support layer of the actuator adjacent to the concave portion of the support layer 125 is fitted, and the rectangular protrusion is fitted to the concave portion of the support layer of the adjacent actuator. The support layer 125 of the present invention performs the function of the membrane 30 of the device described in the preceding application.

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

6A to 6F are cross-sectional views illustrating a method of manufacturing the apparatus shown in FIG. 5. 6A to 6F, the same reference numerals are used for the same members as in FIG.

Referring to FIG. 6A, a protective layer 110 is formed on an active matrix 100 having M × N (M and N are integers) MOS transistors (not shown) and a drain pad 105 formed on one side thereof. To form. 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 protective layer 110 is formed of a silicate glass (PSG) to have a thickness of about 1.0㎛ using a chemical vapor deposition (CVD) method. The protective layer 110 prevents damage to the transistor embedded in the active matrix 100 from subsequent processing.

Subsequently, an etch stop layer 115 is formed on the protective layer 110. The etch stop layer 115 is formed to have a thickness of about 0.1 μm to about 1.0 μm using low pressure chemical vapor deposition (LPCVD). The etch stop layer 115 prevents the protective layer 110 and the active matrix 100 having the transistor embedded therein from being etched during the subsequent etching process.

Subsequently, a sacrificial layer (not shown) is formed on the etch stop layer 115. The sacrificial layer is formed of a PSG having a high concentration of phosphorus (P) to have a thickness of about 1.0 to 3.0 μm using an atmospheric chemical vapor deposition (APCVD) method. In this case, since the sacrificial layer covers the upper portion of the active matrix 100 in which the transistor is embedded, the flatness of the surface is very poor. Thus, the surface of the sacrificial layer is planarized by using spin on glass (SOG) or chemical mechanical polishing (CMP). Subsequently, a portion of the sacrificial layer in which the drain pad 105 is formed is etched to expose a portion of the etch stop layer 115 to form a position where the support portion of the actuator is to be formed.

Referring to FIG. 6B, the support layer 125 may be formed on the exposed etch stop layer 115 and the sacrificial layer (not shown) to a thickness of about 0.1 μm to about 1.0 μm. The support layer 125 is formed of a hard material such as nitride or metal using low pressure chemical vapor deposition (LPCVD). At this time, by forming the support layer 125 while changing the ratio of the reaction gas in the reaction vessel of low pressure, the stress in the support layer 125 is adjusted.

Subsequently, for example, tantalum (Ta) is deposited on the support layer 125 as a first conductive layer 130a by a sputtering method to a thickness of about 200 GPa, and platinum (Pt) is deposited on the second conductive layer 130b thereon. The lower electrode 130 is formed by depositing a thickness of about 1000 mW by a sputtering method. The first signal from the outside is applied to the lower electrode 130, which is a signal electrode, through the transistor and the drain pad 105 embedded in the active matrix 100. Subsequently, a photoresist layer 131 is formed on the lower electrode 130 to perform an “iso-cut” etching process in which the lower electrode 130 is shorted for each pixel.

Referring to FIG. 6C, the platinum layer 130b of the lower electrode is etched by performing an EOP etching process using the photoresist layer 131 as an etching mask. At this time, the platinum layer 130b may remain slightly without being completely etched.

Referring to FIG. 6D, oxygen (O ₂ ) ion implantation is performed on the exposed surface of the photoresist layer 131 as an ion implantation mask, followed by heat treatment. As a result, the tantalum layer 130a having a thickness of 200 가 becomes the insulator 155 of Ta-O, so that the lower electrode 130 is shorted for each pixel. In addition, the remaining platinum layer 130b may also be an insulator 155 of Pt-O, so that the lower electrode 130 is shorted for each pixel.

Referring to FIG. 6E, a strained layer 135 made of a piezoelectric material such as PZT or PLZT is formed on the lower electrode 130 shorted for each pixel. The strained layer 135 is formed to have a thickness of about 0.1 μm to about 1.0 μm, preferably about 0.4 μm by using a sol-gel method, a sputtering method, or a chemical vapor deposition (CVD) method. Phase change is performed by a heat treatment (RTA) method. The deformation layer 135 is deformed by an electric field generated between the upper electrode 140 which is a common electrode and the lower electrode 130 which is a signal electrode.

Subsequently, the upper electrode 140 is formed on one side of the strained layer 135. The upper electrode 140 is formed of a metal having excellent electrical conductivity and reflectivity such as aluminum (Al), silver (Ag), or platinum (Pt) to have a thickness of about 0.1 μm to about 1.0 μm using a sputtering method. The second electrode is applied to the upper electrode 140 from a common electrode line (not shown) from the outside, and at the same time, the upper electrode 140 also functions as a mirror that reflects light incident from the light source.

Next, the upper electrode 140, the strain layer 135, and the lower electrode 130 are sequentially patterned into a predetermined pixel shape. That is, after forming a photoresist layer (not shown) resistant to the material to be etched on the upper electrode 140, the upper electrode 140 is patterned. Subsequently, a photoresist protective layer (not shown) is again formed on the patterned upper electrode 140 and the strained layer 135, and then the strained layer 135 is patterned into a predetermined pixel shape. In this manner, the lower electrode 130 is also patterned into a predetermined pixel shape.

Subsequently, the strained layer 135 and the lower electrode 130 from the portion where the drain pad 105 is formed under the strain layer 135 under the photolithography process to an upper portion of the drain pad 105. The via hole 145 is formed by sequentially etching the support layer 125, the etch stop layer 115, and the protective layer 110. Subsequently, metal via tungsten (W), platinum (Pt), or titanium (Ti) is deposited to form a via contact 150 that electrically connects the drain pad 105 and the lower electrode 130. Accordingly, the via contact 150 is vertically formed from the lower electrode 130 to the top of the drain pad 105 in the via hole 145. Therefore, the first signal applied from the outside is applied to the lower electrode 130 through the transistor, the drain pad 105, and the via contact 150 embedded in the active matrix 100.

Referring to FIG. 6F, a photoresist protective layer (not shown) is formed to cover the exposed surfaces of the upper electrode 140, the strain layer 135, and the lower electrode 130, and then, as an etching mask. The support layer 125 is etched into a predetermined pixel shape.

Subsequently, the sacrificial layer (not shown) is etched using hydrogen fluoride (HF) vapor using the photoresist protective layer as an etching mask to form an air gap (not shown), followed by cleaning and drying. Actuator 200 is formed. Then, rinsing and drying are performed to remove the remaining etching solution to complete the AMA device.

As described above, after completing the M × N thin film type AMA devices, a metal such as chromium (Cr), nickel (Ni), or gold (Au) is sputtered or evaporated into the active matrix 100. Deposited at the bottom to form an ohmic contact (not shown). Next, in general, a tape carrier package (TCP) (not shown) for applying a second signal to the upper electrode 140 as the common electrode and the first signal to the lower electrode 130 as the signal electrode is usually prepared. The active matrix 100 is cut to a predetermined thickness using a photolithography process. 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, in which no pad is formed, is patterned to expose the pad of the AMA panel. Next, the photoresist layer is etched, the active matrix 100 is completely cut into a predetermined shape, and then the pad of the AMA panel and the pad of the TCP are unidirectional conductive film (ACF) (not shown). To complete the manufacture of the thin film AMA module.

In the above-described thin film type optical path control device of the present invention, the first signal transmitted from the outside through the pad of the TCP and the pad of the AMA panel is the MOS transistor, the drain pad 105 and the via contact (built in the active matrix 100). It is applied to the lower electrode 130 which is a signal electrode through the 150. At the same time, a second signal is applied to the upper electrode 140 through the common electrode line from the outside to generate an electric field between the upper electrode 140 and the lower electrode 130. Due to this electric field, the strained layer 135 stacked between the upper electrode 140 and the lower electrode 130 causes deformation. The strained layer 135 contracts in a direction perpendicular to the electric field, and the actuator 200 including the strained layer 135 is bent upward at a predetermined angle. Therefore, the upper electrode 140 which also functions as a mirror on the actuator 200 is inclined in the same direction. Accordingly, the light incident from the light source is reflected by the inclined upper electrode 140 at a predetermined angle, and then passes through the slit to be projected onto the screen to form an image.

In addition, although not shown, the present invention may be applied to a thin film type optical path adjusting apparatus in which an upper electrode is used only as a common electrode to which a second signal is applied, and a mirror for reflecting light incident on the upper electrode is separately formed. Of course. In this case, the mirror is generally formed in a '??' shape horizontally with the upper electrode via the air gap having a support portion in contact with the upper side of the upper electrode.

As described above, according to the manufacturing method of the thin film type optical path control apparatus according to the present invention, in the “Iso-cut” etching process for shorting the lower electrode formed by stacking the first conductive layer and the second conductive layer for each pixel, the The second conductive layer of the lower electrode is etched by an EOP etching process and then oxygen ions are implanted into the exposed surface. As a result, since the first conductive layer becomes an insulator, the lower electrode is shorted for each pixel. In addition, some of the second conductive layers that remain unetched during the EOP etching process may also be, for example, insulators of platinum-oxygen (Pt-O).

Therefore, since the present invention does not perform excessive etching during the “Iso-cut” etching process, the lower electrode may be shorted for each pixel while preventing damage to the lower electrode underlayer (support layer) due to overetching.

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 (5)

Providing an active matrix having a drain pad formed on one side thereof; And I) forming a support layer on top of the active matrix, i) one side of which is in contact with the top of the active matrix and the other side parallel to the active matrix via an air gap, ii) a first conductive layer on top of the support layer; Forming a lower electrode by laminating a second conductive layer; i) implanting oxygen (O ₂ ) ions after etching the second conductive layer of the lower electrode, thereby exposing the exposed portion of the first conductive layer of the lower electrode; Shorting the lower electrode by each pixel by making an insulator, i) forming an actuator on top of the lower electrode, and v) forming an upper electrode on top of the deformation layer. Method of manufacturing a thin film type optical path control device comprising the step. The method of claim 1, wherein the second conductive layer of the lower electrode is etched by an etching process using an etching endpoint. The method of claim 1, wherein the first conductive layer is formed of tantalum (Ta) and the second conductive layer is formed of platinum (Pt). The method of claim 3, wherein the first conductive layer of the lower electrode exposed by the oxygen ion implantation is an insulator of tantalum-oxygen (Ta-O). The method of claim 1, wherein the forming of the actuator comprises: forming the upper electrode on an upper portion of the deforming layer, and then forming the lower electrode from the portion of the deforming layer where the drain pad is formed. And forming a via hole exposing the drain pad by etching the support layer. And depositing a metal in the via hole to form a via contact that electrically connects the drain pad and the lower electrode to the thin film type optical path control apparatus.

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