KR19980078596A - Manufacturing method of thin film type optical path control device which can prevent initial bending of actuator - Google Patents

Abstract

Disclosed is a method of manufacturing a thin film type optical path control device capable of preventing initial bending of an actuator. The method includes providing an active matrix having M × N transistors formed therein and a drain pad formed on one side thereof, forming a protective layer on top of the active matrix, ii) an etch stop layer on the protective layer. Forming a support of the actuator, the method comprising: forming a sacrificial layer on top of the patterned etch stop layer, and iii) flattening the sacrificial layer. Forming a support layer on top of the active matrix and the patterned sacrificial layer, forming a bottom electrode on top of the support layer, forming a strain layer on top of the bottom electrode, and the strain layer And forming an actuator comprising stacking an upper electrode on top of the. According to the above method, by etching the etch stop layer formed on the planarized protective layer to form the support part of the actuator, the thin films to be formed later can be stacked in a flat manner so that the stress distribution of the thin films can be uniform. By preventing the initial warp of the image quality of the image projected on the screen can be improved.

Description

Manufacturing method of thin film type optical path control device which can prevent initial bending of actuator

The present invention relates to a method for manufacturing AMA (Actuated Mirror Arrays), which is a thin film type optical path control device, and more particularly, by removing the step generated from the support of the actuator, the thin films stacked on the top are formed to be flat to cause the initial bending of the actuator ( The present invention relates to a method of manufacturing a thin film type optical path control device capable of preventing initial tilting and improving light efficiency by making a constant reflection angle of light incident from a light source.

In general, a spatial light modulator, which is an apparatus for projecting optical energy onto a screen, may be variously applied to optical communication, image processing, and information display apparatus. Such devices are classified into a direct view type image display device and a projection type image display device according to a method of projecting a light beam incident from a light source onto a screen. CRT (Cathode Ray Tube) or the like is a direct view type image display device, and a liquid crystal display (LCD), a deformable mirror device (DMD), and AMA is a projection type image display device. The CRT apparatus has a high image quality but has a disadvantage in that the screen is not large in size. In other words, as the size of the screen increases, the weight and volume of the device increase, thereby increasing the manufacturing cost. Therefore, a liquid crystal display (LCD) that has a simple optical structure and can be formed thin and has a light weight has been developed. However, the liquid crystal display device has a problem that the efficiency is lowered to have a light efficiency of 1 to 2% due to the polarization of the light beam, the response speed of the liquid crystal material therein is slow, and the device tends to overheat. Accordingly, devices such as DMD or AMA have been developed to solve the above problems. Currently, AMA can achieve 10% or more light efficiency, while DMD devices have about 5% light efficiency. In addition, AMA enhances contrast to produce a brighter and clearer image, and is not affected by the polarity of the incident luminous flux and does not affect the polarity of the luminous flux.

AMA, which is an optical path control device, is classified into a bulk type and a 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 cuts a thin layer of multilayer ceramic and mounts a ceramic wafer having a metal electrode formed therein in an active matrix in which a transistor is built, and then processes it by sawing. This is done by installing a mirror on it. However, the bulk optical path control device requires very high precision in design and manufacturing, and has a problem in that the response speed of the deformable part is slow. Accordingly, a thin film type optical path control apparatus that can be manufactured using a semiconductor process has been developed.

Such a thin film type optical path adjusting device is disclosed in Patent Application No. 96-42197 (name of the invention: thin film type optical path adjusting device which can control the stress of a membrane and a method of manufacturing the same) which the applicant has applied for a patent on September 24, 1996. have.

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

1 and 2, the thin film type optical path control device includes M × N (M, N is an integer) metal oxide semiconductor (MOS) transistors (not shown) and a drain pad on one side. The active matrix 1 in which (5) is formed and the actuator 60 formed on the active matrix 1 are included.

The active matrix 1 includes a protective layer 10 stacked on the active matrix 1 and the drain pad 5, and an etch stop layer 15 stacked on the protective layer 10.

The actuator 60 has a cross section in which one side is in contact with a portion of the etch stop layer 15 in which the drain pad 5 is formed below, and the other side is formed in parallel with the etch stop layer 15 via the air gap 20. Membrane 25 having a structure, lower electrode 30 stacked on top of membrane 25, strained layer 35 stacked on top of lower electrode 30, upper electrode stacked on top of strained layer 35 40, the via hole 45 formed from one side of the strained layer 35 to the drain pad 5 through the lower electrode 30, the membrane 25, the etch stop layer 15, and the protective layer 10. The lower electrode 30 and the drain pad 5 includes a via contact 50 formed to be electrically connected to each other.

Referring to FIG. 1, one side of a plane of the membrane 25 has a rectangular concave portion at a central portion thereof, and the concave portion is formed in a stepped shape toward both edges. The other side of the plane of the membrane 25 has a rectangular protrusion that narrows stepwise toward the central portion corresponding to the concave portion. Therefore, the protrusion of the membrane of the actuator adjacent to the concave portion of the membrane 25 is fitted, and the rectangular protrusion is fitted to the concave portion of the membrane of the adjacent actuator.

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

3A to 3D are manufacturing process diagrams of the apparatus shown in FIG. 2. 3A to 3D, the same reference numerals are used for the same members as in FIG.

Referring to FIG. 3A, a protection composed of Phosphor Silicate Glass (PSG) on top of an active matrix 1 having M × N transistors (not shown) and a drain pad 5 formed on one side thereof. Layer 10 is laminated. The protective layer 10 is formed to have a thickness of about 1.0 to about 2.0 μm using a chemical vapor deposition (CVD) method. The protective layer 10 protects the active matrix 1 in which the transistor is embedded during subsequent processing.

The etch stop layer 15 is stacked on the passivation layer 10 by using nitride. The etch stop layer 15 is formed to have a thickness of about 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 and damaged during the subsequent etching process.

The sacrificial layer 17 is stacked on the etch stop layer 10. The sacrificial layer 17 is formed of phosphorous silicate glass (PSG) having a high concentration of phosphorus (PG) so as to have a thickness of about 1.0 to 3.0 μm using the Atmospheric Pressure Vapor Deposition (APCVD) method. Form. In this case, since the sacrificial layer 17 covers the upper portion of the active matrix 1 in which the transistor is embedded, the flatness of the surface thereof is very poor. Accordingly, the surface of the sacrificial layer 17 is planarized by using a spin on glass (SOG) method or a chemical mechanical polishing (CMP) method. Next, a portion of the sacrificial layer 17 in which the drain pad 5 is formed is etched to expose a portion of the etch stop layer 15.

Referring to FIG. 3B, the membrane layer 24 is stacked on the exposed etch stop layer 15 and on the sacrificial layer 17 to have a thickness of about 0.1 to 1.0 μm. The membrane layer 24 is formed of silicon carbide at a temperature of 200 to 300 ° C. using a plasma enhanced CVD (PECVD) method. At this time, the silicon carbide is prepared by depositing silicon (Si) and carbon (C) generated from the liquid (liquid) C ₆ H ₁₈ Si ₂ . Alternatively, the silicon carbide may be prepared by depositing silicon and carbon generated from a mixture of SiH ₄ and CH ₄ . Subsequently, the membrane layer 24 made of silicon carbide is heat-treated at a temperature of 600 ° C. or lower to adjust the stress in the membrane layer 24.

The lower electrode layer 29 is stacked on the membrane layer 24 using a metal such as platinum (Pt) or tantalum (Ta). The lower electrode layer 29 is formed to have a thickness of about 500 to 2000 mW using a sputtering method. The lower electrode layer 29 is later patterned into the lower electrode 30. Subsequently, the lower electrode layer 29 is separated for each pixel, and the lower electrode layer 29 is isocutted for a short circuit of a signal applied to the lower electrode 30.

Referring to FIG. 3C, the first layer 34 is formed on the lower electrode layer 29 using a piezoelectric material such as PZT or PLZT. The first layer 34 is formed to have a thickness of about 0.1-1 .0 μm, preferably about 0.4 μm by using a sol-gel method, and then rapid thermal Annealing: Heat transfer by RTA). The first layer 34 is later patterned into a strained layer 35. The upper electrode layer 39 is stacked on top of the first layer 34. The upper electrode layer 39 is formed of a metal having excellent electrical conductivity and reflectivity such as aluminum or platinum so as to have a thickness of about 500 to 2000 kPa using a sputtering method. The upper electrode layer 39 is later patterned into the upper electrode 40.

Referring to FIG. 3D, after applying a photoresist (not shown) on the upper electrode layer 39, the upper electrode layer 39 is patterned into a predetermined shape to form the upper electrode 40. The second electrode (bias signal) is applied to the upper electrode 40 from a common electrode line (not shown). At the same time, the upper electrode 40 also serves as a mirror for reflecting light incident from a light source (not shown). When the upper electrode layer 39 is patterned as described above, stripes 55 are formed together at the center of the upper electrode 40. When the actuator 60 causes deformation, the stripe 55 uniformly bends the upper electrode 40 to prevent diffuse reflection of light incident from the light source.

Subsequently, the strained layer 35 and the lower electrode 30 are formed using the same method as the method of patterning the first electrode 34 and the lower electrode layer 29 to the upper electrode layer 39. The first electrode (image signal) is applied to the lower electrode 30 through the MOS transistor from the outside. Subsequently, the strained layer 35, the lower electrode 30, the membrane layer 24, the etch stop layer 15, and the protective layer 10 are sequentially disposed from one side of the strained layer 35 to the top of the drain pad 5. The via hole 43 is formed from the strained layer 35 to the drain pad 5 by etching. Subsequently, a via contact 50 is formed to electrically connect the drain pad 5 and the lower electrode 30 to a metal such as tungsten (W), platinum, or titanium using a sputtering method. Thus, the via contact 50 is formed vertically from the lower electrode 30 to the drain pad 5 in the via hole 45. Therefore, the first signal transmitted from the transistor embedded in the active matrix 1 is applied to the lower electrode 30 through the drain pad 5 and the via contact 50. After the membrane layer 24 is patterned to form the membrane 25, the sacrificial layer 17 is etched with hydrogen fluoride (HF) vapor, washed and dried to complete an AMA device.

In the above-described thin film type optical path adjusting device, the first signal transmitted from the transistor embedded in the active matrix 1 is applied to the lower electrode 30 through the drain pad 5 and the via contact 50. In addition, a second signal is applied to the upper electrode 40 to generate an electric field between the upper electrode 40 and the lower electrode 30. By this electric field, the deformation layer 35 formed between the upper electrode 40 and the lower electrode 30 causes deformation. The deformation layer 35 causes deformation in a direction perpendicular to the electric field, and the actuator 60 including the deformation layer 35 is bent upward. Therefore, the upper electrode 40 on the actuator 60 is also bent in the same direction. The light beam incident from the light source is reflected by the upper electrode 40 bent at a predetermined angle, and then is projected onto the screen to form an image.

In the thin film type optical path adjusting device described in the preceding application, in order to form a support part of the actuator, a sacrificial layer is laminated to planarize the surface, and after etching the part where the support part of the actuator is to be formed, the actuator is formed on the sacrificial layer. Thin films were laminated. At this time, a step equal to the thickness of the sacrificial layer etched is generated between the portion where the support portion of the actuator is formed and the portion other than that. As a result, the stress distribution between the support portion and the remaining portions of the actuator among the thin films becomes uneven, which causes the initial bending of the actuator. As a result, the angle of reflection of the light incident from the light source is not constant. There is a problem of deterioration.

Accordingly, an object of the present invention is to remove the step between the support and the remaining portion of the actuator to form a thin film to be stacked on the top, to uniformly distribute the stress between the thin film to prevent the initial bending of the actuator, improving the light efficiency It is to provide a method of manufacturing a thin film type optical path control device that can be made.

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

FIG. 2 is a cross-sectional view taken along line A′A ′ of the apparatus shown in FIG. 1.

3A to 3D are manufacturing process diagrams of the apparatus 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 taken along line B′B ′ of the apparatus shown in FIG. 4.

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

<Explanation of symbols for main parts of drawing>

100: Active matrix 105: Drain pad

110: protective layer 115: etching prevention layer

120: sacrificial layer 125: support layer

130: lower electrode 135: strained layer

140: upper electrode 145: via hole

150: via contact 155: air gap

160: stripe 200: actuator

In order to achieve the above object, the present invention provides an active matrix having M × N transistors embedded therein and a drain pad formed on one side thereof, and forming a protective layer on top of the active matrix; Forming an etch stop layer on top of the layer, iii) patterning the etch stop layer, iii) forming a sacrificial layer on top of the patterned etch stop layer, and iii) planarizing the sacrificial layer. Forming a support of the actuator, forming a support layer on top of the active matrix and the patterned sacrificial layer, forming a bottom electrode on top of the support layer, and forming a strained layer on top of the bottom electrode And forming an actuator on top of the strained layer. It provides a method of manufacturing a thin film type optical path control device comprising.

In the thin film type optical path adjusting device according to the present invention, the first signal applied from the outside is applied to the lower electrode through the transistor, the drain pad, and the via contact embedded in the active matrix. At the same time, a second signal is applied to the upper electrode from the outside to generate an electric field between the upper electrode and the lower electrode. Due to this electric field, the strain layer formed between the upper electrode and the lower electrode causes deformation. The strained layer contracts in a direction perpendicular to the electric field, so the actuator including the strained layer is bent upwards at a predetermined angle. Light incident from the light source is reflected by the upper electrode inclined at a predetermined angle, and then is projected onto the screen to form an image.

Therefore, according to the manufacturing method of the thin film type optical path control apparatus according to the present invention, by forming an etch stop layer on the flattened protective layer and undercutting a portion of the etch stop layer to form a support part of the actuator, the support part and the remaining part of the actuator The step between them can be eliminated. Therefore, the thin films to be formed later can be stacked uniformly and evenly, thereby making it possible to uniformly distribute the stresses between the thin films, thereby preventing the initial bending of the actuator and making the reflection angle of the light incident from the light source constant. The image quality of the image projected on can be improved.

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

4 is a plan view of a thin film type optical path control device according to an embodiment of the present invention, Figure 5 is a cross-sectional view taken along the line B 'B' of the device shown in FIG.

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.

The active matrix 100 is made of a semiconductor substrate such as silicon (Si) or an insulating material such as glass or alumina (Al ₂ O ₃ ). The active matrix 100 has a built-in MOS transistor for receiving a first signal from the outside to perform a switching operation. The active matrix 100 includes a protective layer 110 stacked on the active matrix 100 and the drain pad 105 and an etch stop layer 115 stacked on the protective layer 110.

The actuator 200 has a cross-section formed in parallel with the etch stop layer 115 via one side of the etch stop layer 115 at one side thereof in contact with a portion where the drain pad 105 is formed and the other side through the air gap 155. A supporting layer 125 having a support layer 125, a lower electrode 130 stacked on top of the support layer 125, a strained layer 135 stacked on top of the lower electrode 130, and one side upper portion of the strained layer 135. The upper electrode 140 is stacked on. The lower electrode 130, the support layer 125, the etch stop layer 115, and the etch stop layer 115 may be formed at one side of the support layer 125, which is in contact with the portion where the drain pad 105 is formed below. And a via contact 155 is formed in the via hole 150 formed vertically through the protective layer 110 to the drain pad 105 so that the lower electrode 130 and the drain pad 105 are electrically connected to each other. do.

Referring to FIG. 4, one side of the plane of the support layer 125 has a concave portion having a rectangular shape at the center thereof, and the concave portion is formed to have a stepped shape toward both edges. In addition, the other side of the plane of the support layer 125 has a rectangular protrusion that narrows stepwise toward the center 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 125 is fitted, and the rectangular projection is fitted into the concave portion of the support layer of the adjacent actuator.

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 accompanying drawings.

6a to 6e show a manufacturing process diagram of the apparatus shown in FIG. 6A to 6E, the same reference numerals are used for the same members as in FIG.

Referring to FIG. 6A, a protective layer may be formed by using an silicate glass PSG on an active matrix 100 having M × N MOS transistors (not shown) and a drain pad 105 formed on one side thereof. 110) are stacked. The protective layer 110 is formed to have a thickness of about 2000 GPa using a chemical vapor deposition (CVD) method. The protective layer 110 protects the active matrix 100 in which the transistor is embedded during subsequent processing.

An etch stop layer 115 is formed on the passivation layer 110 by using nitride. The etch stop layer 115 may be formed using a plasma enhanced CVD (PECVD) method. It is formed to have a thickness of about 0㎛. The etch stop layer 115 may prevent the protective layer 110, the active matrix 100, etc. from being etched during the subsequent etching process. Subsequently, the remaining portion of the etch stop layer 115 is left only at the position where the support portion of the actuator 200 is to be formed. By removing by etching by a thickness of about 6㎛, the support portion of the actuator 200 is formed. Preferably, a portion of the etch stop layer 115 on which the support portion of the actuator 200 is to be formed is etched a portion of the etch stop layer 115 to protrude in a rectangular shape. That is, the portion of the active matrix 100 except for the portion in which the drain pad 105 is formed is 0.2-2. A portion of the etch stop layer 115 is etched and removed to have a thickness of about 4 μm.

Referring to FIG. 6B, a sacrificial layer 120 is stacked on the etch stop layer 115. The sacrificial layer 120 is formed of phosphorus silicate glass (PSG) having a high concentration of phosphorus (PG) to have a thickness of about 1.5 to about 2.0 μm using an atmospheric chemical vapor deposition (APCVD) method. The sacrificial layer 120 functions to facilitate lamination to form the actuator 200. In this case, since the sacrificial layer 120 covers the upper portion of the protective layer 110 patterned to form the support of the actuator 200, the surface thereof is not flat. Therefore, the upper portion of the sacrificial layer 120 is polished to have the same height as the etch stop layer 115 by using the CMP method, thereby exposing the etch stop layer 115 below. Therefore, the position at which the supporting part of the actuator 200 is to be formed is a state in which the etch stop layer 115 is exposed, and the remaining part is a state in which the sacrificial layer 120 is filled, and the upper surface thereof is flat.

Conventionally, after stacking the sacrificial layer by etching to remove the portion to be formed the support portion of the actuator, a step by the thickness of the etched sacrificial layer occurred between the portion in which the support portion of the actuator is formed and other portions. Due to this step, the stress distribution between the support part and the rest of the actuator is uneven, which causes the initial bending of the actuator. On the other hand, in the present invention, the step is not generated at the support of the actuator by undercutting and removing the remaining part of the etch stop layer formed on the planarized protective layer, leaving only the position where the support of the actuator is to be formed later. Subsequently, the thin films subsequently stacked may be formed flat.

Referring to FIG. 6C, the first layer 124 is stacked on the exposed etch stop layer 115 and on the sacrificial layer 120. The first layer 124 is formed to have a thickness of about 0.01 to 1.0 탆 using a low pressure chemical vapor deposition (LPCVD) method of a hard material such as nitride or metal. The first layer 124 is later patterned into a support layer 125. The support layer 125 of the present invention performs the function of the membrane described in the prior application.

A lower electrode layer 129 made of a metal such as platinum (Pt), tantalum (Ta), or platinum-tantalum (Pt-Ta) is stacked on the first layer 124. The lower electrode layer 129 is formed to have a thickness of about 0.01 to 1.0 탆 using a sputtering method or a chemical vapor deposition method. At the same time, the lower electrode layer 129 is iso-cutted in a direction parallel to the direction in which the actuator 200 is formed in order to apply an independent first signal for each pixel. The lower electrode layer 129 is later patterned with a lower electrode 130 to which a first signal is applied. A second layer 134 made of a piezoelectric material such as PZT or PLZT is stacked on the lower electrode layer 129. The second layer 134 has a thickness of about 0.1 to 1.0 µm, preferably about 0.4 µm using a sol-gel method, a sputtering method, or a chemical vapor deposition (CVD) method. Form to have. In addition, the piezoelectric material constituting the second layer 134 is subjected to heat treatment using a rapid heat treatment (RTA) method to phase change. Subsequently, the piezoelectric material constituting the second layer 134 is polarized. The second layer 134 is later patterned into the strained layer 135.

The upper electrode layer 139 is stacked on top of the second layer 134. The upper electrode layer 139 is formed of a metal having electrical conductivity and reflectivity, such as aluminum, silver, or platinum, to have a thickness of about 0.01 to 1.0 탆 using a sputtering method. The upper electrode layer 139 is then patterned into the upper electrode 140.

Referring to FIG. 6D, the upper electrode layer 139 is patterned to form an upper electrode 140 having a predetermined pixel shape. At this time, the stripe 160 is formed together on one side of the upper electrode 140. The second signal is applied to the upper electrode 140 from a common electrode line (not shown). Subsequently, the second layer 134 and the lower electrode layer 129 are sequentially patterned to form a pixel layer having a larger area than the upper electrode 140 and a pixel layer having a larger area than the strain layer 135. A lower electrode 130 having a shape is formed. When the second signal is applied to the upper electrode 140 and the first signal is applied to the lower electrode 130, an electric field is generated between the upper electrode 140 and the lower electrode 130. The strained layer 135 causes deformation by this electric field.

Subsequently, the strained layer 135, the lower electrode 130, the support layer 125, the etch stop layer 115, and the protective layer 110 from one side upper portion of the strained layer 135 to an upper portion of the drain pad 105. The via holes are sequentially etched to form via holes 145. Subsequently, a via contact 150 is formed in the via hole 145 by sputtering or chemical vapor deposition using a metal having excellent electrical conductivity such as tungsten (W), platinum, or titanium (Ti). The via contact 150 is formed from the drain pad 105 to the lower electrode 130 to electrically connect the drain pad 105 and the lower electrode 130. 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. The first layer 124 is patterned to form a support layer 125 having a pixel shape having a larger area than the lower electrode 130.

Referring to FIG. 6E, the sacrificial layer 120 is etched using hydrogen fluoride (HF) vapor to form an air gap 155 at the position of the sacrificial layer 120, and then the remaining etching solution is removed. Rinse and dry treatment is performed to complete the AMA device.

After completing the M × N thin film type AMA devices as described above, the active matrix 100 may be sputtered or evaporated on a metal such as chromium (Cr), nickel (Ni), or gold (Au). Is deposited at the bottom of the to form an ohmic contact (not shown). In addition, an active matrix may be prepared in preparation for bonding a tape carrier package (TCP) (not shown) for applying a second signal to a subsequent upper electrode 140 and a first signal to the lower electrode 130. 100 is cut to a predetermined thickness. Subsequently, a photoresist layer (not shown) is formed over the pad of the AMA panel so that the pad of the AMA panel (not shown) has a sufficient height in preparation for TCP bonding. Subsequently, a portion of the photoresist layer on which the pad is formed is patterned to expose the pad of the AMA panel. Subsequently, the photoresist layer is etched and removed, the active matrix 100 is completely cut into a predetermined shape, and then the pad of the AMA panel and the pad of TCP are connected using an anisotropic conductive film (ACF) (not shown). This completes the manufacture of the thin film AMA module.

In the above-described thin film type optical path control device according to 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 transistor, a drain pad 105 and a via contact (embedded in the active matrix 100). It is applied to the lower electrode 130 through 150. At the same time, the second signal is applied to the upper electrode 140 from the outside through the common electrode line, thereby generating an electric field between the upper electrode 140 and the lower electrode 130. Due to this electric field, the strain layer 135 between the upper electrode 140 and the lower electrode 130 causes deformation. The strained layer 135 contracts in a direction perpendicular to the generated electric field, and the actuator 200 including the strained layer 135 is bent upward at a predetermined angle. Since the upper electrode 140, which also functions as a mirror that reflects light, is formed on the actuator 200, the upper electrode 140 is inclined together with the actuator 200. Accordingly, the upper electrode 140 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.

According to the manufacturing method of the thin film type optical path control apparatus according to the present invention, the support portion of the actuator by removing the remaining portion except the portion of the etching prevention layer formed on the planarized protective layer to be formed under the cut (under cut) And the step between the rest can be eliminated. Therefore, since the thin films to be formed later can be stacked uniformly and evenly, the distribution of stress between the thin films constituting the actuator can be made uniform. As a result, it is possible to prevent the initial bending of the actuator, thereby improving the image quality of the image projected on the screen by making the angle of reflection of the light incident from the light source constant.

Although the above has been described 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 M × N transistors embedded therein and having drain pads formed on one side thereof; Iii) forming a protective layer on top of the active matrix, ii) forming an etch stop layer on top of the protective layer, iii) patterning the etch stop layer, iii) on top of the patterned etch stop layer Forming a support of the actuator, comprising: forming a sacrificial layer, and iii) planarizing the sacrificial layer; And forming a support layer on top of the active matrix and the patterned sacrificial layer, forming a lower electrode on the support layer, forming a strain layer on the lower electrode, and an upper portion of the strain layer. Forming an actuator comprising the step of forming an upper electrode in the thin film type optical path control device manufacturing method comprising the step of forming. The thin film type optical path control method of claim 1, wherein the forming of the etch stop layer comprises forming nitride to have a thickness of about 1.2 μm to about 2.0 μm using a PECVD method. Method of manufacturing the device. The thin film type optical path of claim 1, wherein the patterning of the etch stop layer comprises patterning the etch stop layer to protrude in a rectangular shape only on an upper portion of a portion of the active matrix in which the drain pad is formed. Method of manufacturing the regulating device. The thin film type optical path of claim 3, wherein the patterning of the etch stop layer comprises patterning a portion of the anti-cut layer except for the protruding portion to have a thickness of 0.2 μm to 0.4 μm. Method of manufacturing the regulating device. 2. The method of claim 1, wherein the planarizing of the sacrificial layer is performed by exposing the protruding portion of the etch stop layer by using a chemical mechanical polishing (CMP) method. Way.