KR19980054847A - Manufacturing method of thin film type optical path control device - Google Patents

Abstract

A method of manufacturing a thin film type optical path control device capable of improving the flatness of an actuator is disclosed. The method includes providing an active matrix in which M × N transistors are embedded and a drain is formed on one side, forming a sacrificial layer on the active matrix, and a hard mask on the sacrificial layer. Forming a first mask layer for forming, forming a second mask layer on top of the first mask layer, patterning the sacrificial layer, and forming a membrane on the patterned sacrificial layer, the Forming a lower electrode on the membrane, forming a strained layer on the lower electrode, forming an upper electrode on the strained layer, and the upper electrode, the strained layer, the lower electrode, and Patterning the membrane. According to the above method, the sacrificial layer can be patterned more efficiently, thereby minimizing the influence on the actuator due to the sacrificial layer etching, thereby forming a stable actuator, and preventing the initial tilting of the actuator. The reflection angle of can be made constant.

Description

Manufacturing method of thin film type optical path control device

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 accurately patterning a sacrificial layer by using a hard mask made of silicate (SiO ₂ ). The present invention relates to a method for manufacturing a thin film type optical path control device capable of minimizing the influence on the actuator formed on the substrate to form a stable actuator, thereby making the reflection angle of the light beam incident from the light source constant.

In general, an optical path adjusting apparatus or an optical modulator capable of adjusting a light beam incident from a light source may be variously applied to optical communication, image processing, and information display apparatus. In general, such devices are classified into two types according to their optical properties.

One type is a direct view type image display device, such as a CRT (Cathode Ray Tube), and the other type is a projection type image display device, a liquid crystal display (LCD), an AMA, or a deformable mirror device (DMD). ) And the like. Although the CRT device has excellent image quality, there is a problem that the weight and volume of the device increase and the manufacturing cost increases as the screen is enlarged. On the other hand, the liquid crystal display (LCD) has an advantage in that the optical structure is simple to form a thin layer so that the weight of the device can be reduced and the volume can be reduced. However, the liquid crystal display has a disadvantage in that the efficiency is low enough to have a light efficiency of 1 to 2% due to the polarized light, the response speed of the liquid crystal material is slow, and the inside thereof is easily overheated. Therefore, an image display device such as AMA or DMD has been developed to solve the above problem. Currently, AMA has a light efficiency of 10% or more, compared to a DMD device having a light efficiency of about 5%.

The AMA is a device that can adjust the luminous flux so that each of the mirrors installed therein reflects the light incident from the light source at a predetermined angle, and the reflected light passes through a slit and is projected onto the screen to form an image. to be. Therefore, the structure and operation principle thereof are simple, and high light efficiency can be obtained compared to a liquid crystal display device or a DMD. In addition, the contrast is improved to obtain a bright and clear image. The mirrors built into the AMA are inclined by the electric field generated in correspondence with the slits. Therefore, the luminous flux incident from the light source is adjusted at a predetermined angle to form an image on the screen. In general, each actuator causes deformation in accordance with the electric field generated by the applied electric image signal and the bias voltage.

When the actuator causes deformation, each of the mirrors mounted on top of the actuator is inclined. Accordingly, the inclined mirrors can reflect light incident from the light source at a predetermined angle. Piezoelectric materials such as PZT (Pb (Zr, Ti) O ₃ ), or PLZT ((Pb, La) (Zr, Ti) O ₃ ) are used as actuators for driving the respective mirrors. In addition, the actuator can be configured as a warping material such as PMN (Pb (Mg, Nb) O ₃ ).

The optical path control device using AMA is largely classified into a bulk type and a thin film type. The bulk optical path control device is described, for example, in US Pat. Nos. 5,085,497 (issued to Gregory Um, et al.), 5,159,225 (issued to Gregory Um, et al.), 5,175,465 (issued to Gregory Um, et. al.) and the like. The bulk optical path control device cuts a thin layer of multilayer ceramic, mounts a ceramic wafer having a metal electrode therein in an active matrix including a transistor, and then processes it by sawing and mirrors on the top. It is done by installation. However, bulk devices require high precision in design and manufacture because the actuators must be separated by a sawing method, and the response speed of the deformation part is slow. Therefore, a thin film type optical path control apparatus that can be manufactured using a semiconductor manufacturing process has been developed.

Such a thin film type optical path control device is disclosed in Patent Application No. 95-13353 (name of the invention: a method of manufacturing an optical path control device), filed by the applicant on May 26, 1995. 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.

As shown in Fig. 1 and Fig. 2, the thin film type optical path adjusting device is composed of an active matrix 1 and an actuator 3 formed on the active matrix 1.

The active matrix 1 is composed of a semiconductor such as silicon (Si), and includes M × N (M, N is an integer) MOS (Metal Oxide Semiconductor) transistors (not shown). In addition, the active matrix 1 may be formed of an insulating material such as glass, alumina (Al ₂ O ₃ ), or the like. A pad 5 is formed on one side of the active matrix 1. The pad 5 is electrically connected to a transistor embedded in the active matrix 1.

The actuator 3 includes a membrane 7, a plug 9, a bottom electrode 11, an active layer 15 and a top electrode 17. It is composed of

As shown in FIG. 1, the membrane 7 has a rectangular concave portion formed at one side of a center portion of the actuator 3, and a quadrangular protrusion portion corresponding to the concave portion is formed at the other side thereof. . The protrusion of the membrane of the actuator adjacent to the concave portion of the membrane 7 is fitted, and the protrusion of the membrane 7 is fitted into the concave portion of the adjacent actuator. Also, referring to FIG. 2, a portion of one side of the membrane 7 is in contact with an upper portion of the active matrix 1 in which the pad 5 is formed, and the other side of the membrane 7 is disposed through an air gap 8. It is formed to be parallel to the matrix 1.

The plug 9 is formed perpendicular to the portion of the membrane 7 in which the pad 5 is formed. The plug 9 is electrically connected to the pad 5. The lower electrode 11 is formed on the membrane 7, and the deformable part 15 is formed on the lower electrode 11. The upper electrode 17 is formed on the deformation part 15. The upper electrode 17 performs not only a function of an electrode but also a mirror reflecting an incident light beam.

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

3A to 3E show a manufacturing process diagram of the apparatus shown in FIG. Referring to FIG. 3A, a sacrificial layer 2 made of Phospho-Silicate Glass (PSG) is stacked on an active matrix 1 having a pad 5 formed on one side thereof. The sacrificial layer 2 is formed to have a thickness of about 1.0 to about 2.0 μm using a chemical vapor deposition (CVD) method. Subsequently, a photo resist (not shown) is applied on the sacrificial layer 2, and then a portion of the sacrificial layer 2 is etched to pad the top 5 of the active matrix 1. Expose the part in which is formed.

Referring to FIG. 3B, a membrane 7 having a thickness of about 0.1 to 1.0 μm is stacked on the exposed portion of the active matrix 1 and the sacrificial layer 2. The membrane 7 is formed by sputtering or chemical vapor deposition (CVD) of silicon nitride (Si ₃ N ₄ ). Subsequently, a portion of the membrane 7 formed on the exposed portion of the active matrix 1 is etched by the conventional photolithography method to form the opening 6.

Through the opening 6, a plug 9 made of a metal having good electrical conductivity such as tungsten (W) or titanium (Ti) is formed. The plug 9 is formed using a lift-off method to be electrically connected to the pad 5.

The lower electrode 11 is stacked on the membrane 7 in which the opening 6 is formed. The lower electrode 11 is formed to have a thickness of about 500 to 2000 micrometers of platinum (Pt) or platinum-titanium (Pt-Ti) by using vacuum evaporation or sputtering. The lower electrode 11 is electrically connected to the plug 9, and thus the pad 5, the plug 9 and the lower electrode 11 are electrically connected to each other.

Referring to FIG. 3C, the deformation part 15 is stacked on the lower electrode 11. The deformable portion 15 is formed to have a thickness of about 0.01 to 1.0 탆 using piezoelectric materials such as PZT or PLZT, or electrostrictive materials such as PMN. The deformable portion 15 is formed using a sol-gel method or a chemical vapor deposition method (CVD).

The upper electrode 17 is stacked on the deformable portion 15. The upper electrode 17 is formed to have a thickness of about 500 to 1000 mW by sputtering or vacuum deposition of a metal such as aluminum (Al) or silver (Ag). Subsequently, the upper electrode 17, the deformable portion 15, the lower electrode 11, and the membrane 7 are sequentially etched from the top by using a photolithography method to pattern the pattern. In this case, the upper electrode 17, the deformable part 15, and the lower electrode 11 are etched to be separated from the upper electrode, the deformable part, and the lower electrode of an adjacent actuator. At the same time, the membrane 7 is etched to be connected with the membrane of the adjacent actuator. The protective layer 18 is formed by coating a photoresist on a side surface generated when the upper electrode 17 and the actuators are separated from each other.

Referring to FIG. 3D, the sacrificial layer 2 is etched using an oxide buffered etchant (BOE) in which ammonium fluoride (NH 4 F) and hydrogen fluoride (HF) are mixed to form an air gap. (8) is formed. In addition, the protective layer 18 is removed by a wet etching method, and the remaining etching solution is washed with deionized water. Subsequently, a photoresist is coated on the upper electrode 17 to form a mask 19.

Referring to FIG. 3E, the portion of the membrane 7 connected to the membrane of the adjacent actuator is etched using the reactive ion etching (RIE) method using the mask 19 as an etching mask. Then, the mask 19 is removed by an oxygen (O ₂ ) plasma method to complete the AMA device.

In the above-described thin film type optical path adjusting device, the image signal generated from the MOS transistor embedded in the active matrix 1 is applied to the lower electrode 11 through the pad 5 and the plug 9. At the same time, a bias voltage is applied to the upper electrode 17 to generate an electric field between the upper electrode 17 and the lower electrode 11. By this electric field, the deformation | transformation part 15 shrinks in the direction perpendicular | vertical to an electric field. Accordingly, the actuator 3 is bent in the opposite direction to the direction in which the membrane 7 is formed, and the upper electrode 17 on the actuator 3 reflects the light beam incident from the light source. The light beam reflected by the upper electrode 17 is projected onto the screen through the slit to form an image.

In the thin film type optical path adjusting device described in the foregoing application, the sacrificial layer made of in-silicate glass (PSG) is patterned after applying a photo resist as a mask thereon to form a support portion of the actuator. At this time, the photoresist mask is easily detached due to poor adhesion to the sacrificial layer, and when the sacrificial layer is subsequently etched with hydrogen fluoride (HF) vapor due to such detachment, an etching solution is formed on the detached portion. As this penetrates and receives an attack, the sacrificial layer is not patterned into a desired shape. That is, the undercut is generated under the attack due to excessive etching. Therefore, there is a problem in that the thin films to be laminated later are unevenly stacked. In the undercut portion of the sacrificial layer, the subsequent thin films are excessively stacked so that the entire thin films are unevenly stacked, thereby causing distortion and initial tilting of the actuator, and thereby stress between the thin films deposited in a subsequent process. Since the distribution is not uniform, there is a problem of accelerating deterioration of the entire actuator.

Accordingly, an object of the present invention is to accurately pattern the sacrificial layer by increasing the adhesion between the sacrificial layer and the mask by using a hard mask made of silicate (SiO ₂ ), thereby minimizing the effect on the actuator due to the sacrificial layer etching. The present invention provides a method of manufacturing a thin film type optical path control device which can form a stable actuator, and can prevent the twist and initial tilt of the actuator to make the reflection angle of the light beam incident from the light source constant.

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 3E are manufacturing process diagrams of the apparatus shown in FIG.

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>

31: active matrix 32: actuator

33: drain 35: protective layer

37: anti-etching layer 39: sacrificial layer

41: first mask layer 43: second mask layer

45 membrane 47 lower electrode

49 strain layer 51 upper electrode

53: air gap 55: beer hole

57: Beer Contact

The present invention to achieve the above object,

Providing an active matrix having M × N transistors embedded therein and having a drain formed on one side thereof;

Forming a sacrificial layer on top of the active matrix;

Forming a first mask layer for a hard mask by using silicate (SiO ₂ ) on the sacrificial layer;

Forming a second mask layer on the first mask layer;

Patterning the sacrificial layer;

Forming a membrane on top of the patterned sacrificial layer;

Forming a lower electrode on the membrane;

Forming a strained layer on the lower electrode;

Forming an upper electrode on the strain layer; And

It provides a method for manufacturing a thin film type optical path control device comprising the step of patterning the upper electrode, the strain layer, the lower electrode and the membrane in turn.

In the above-described thin film type optical path control apparatus according to the present invention, a bias voltage is applied to the upper electrode, and at the same time, an image signal is applied to the lower electrode through the transistor and the drain and via contact embedded in the active matrix. Accordingly, an electric field is generated between the upper electrode and the lower electrode, and the strained layer between the upper electrode and the lower electrode causes deformation by this electric field. The strained layer contracts in a direction perpendicular to the electric field, so the actuator including the strained layer is bent at a predetermined angle. The upper electrode, which also functions as a mirror that reflects the light beam, is formed on the actuator and is inclined with the actuator. Accordingly, the upper electrode reflects the light beam incident from the light source at a predetermined angle, and the reflected light beam passes through the slit to form an image on the screen.

Accordingly, in the thin film type optical path adjusting device according to the present invention, when the sacrificial layer is patterned to form the support part of the actuator, the first mask for the hard mask is applied to the upper portion of the sacrificial layer, thereby providing The adhesion may be improved to minimize the influence on the actuator due to the etching of the sacrificial layer, and the sacrificial layer may be patterned into a desired shape. In addition, the torsion and initial tilting of the actuator formed in the subsequent process can be prevented to make the reflection angle of the light beam incident from the light source constant.

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

4 is a plan view showing 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 shown in FIG. 4.

4 and 5, the thin film type optical path adjusting apparatus according to the present invention includes an active matrix 31 and an actuator 32 formed on the active matrix 31.

The active matrix 31 may include a drain 33 formed on one surface of the active matrix 31, a passivation layer 35 stacked on the active matrix 31 and the drain 33. And an etch stop layer 37 stacked on the protective layer 35.

The actuator 32 has a membrane in which one side is in contact with a portion of the etch stop layer 37 in which a drain 33 is formed at the lower side thereof, and the other side is parallel to the etch stop layer 37 via an air gap 53 ( membrane 45, a bottom electrode 47 stacked on top of membrane 45, an active layer 49, and a deformation layer 49 stacked on top of bottom electrode 47. A top electrode 51 stacked on one side of the top, a strain layer 49, a bottom electrode 47, a membrane 45, an etch stop layer 37, and a protective layer from the other side of the strain layer 49. Via holes 55 formed vertically through the drain 33 through 35 and via contacts 57 formed in the via holes 55.

In addition, referring to FIG. 4, one side of the membrane 45 has a concave portion having a rectangular shape at the center thereof, and the concave portion is formed in a stepped shape toward both edges. The other side of the membrane 45 has a quadrangular protrusion that narrows stepwise toward the central portion corresponding to the concave portion. Therefore, the concave portion of the membrane of the actuator adjacent to the concave portion of the membrane 45 is fitted, and the rectangular projection is fitted to the concave portion of the adjacent membrane.

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

6a to 6e 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 35 is disposed on an active matrix 31 having M × N metal oxide semiconductor (MOS) transistors (not shown) and a drain 33 formed on one surface thereof. )). The active matrix 31 is made of a semiconductor such as silicon, or made of glass or an insulating material such as alumina (Al ₂ O ₃ ). The protective layer 35 is formed to have a thickness of about 0.01 to 1.0 μm using phosphorus silicate glass (PSG) using a chemical vapor deposition (CVD) method. The protective layer 35 prevents the transistor embedded in the active matrix 31 from being damaged during subsequent processing.

An etch stop layer 37 is stacked on the passivation layer 35. The etch stop layer 37 is formed to have a thickness of about 1000 to 2000 GPa using a low pressure chemical vapor deposition (LPCVD) method. The etch stop layer 37 prevents the active matrix 31 and the protective layer 35 from being etched due to the subsequent etching process.

A sacrificial layer 39 is stacked on the etch stop layer 37. The sacrificial layer 39 is formed of a silicate glass (PSG) to have a thickness of about 1.0 to about 2.0 μm by an Atmospheric Pressure Vapor Deposition (APCVD) method. In this case, since the sacrificial layer 39 covers the upper portion of the active matrix 31 in which the transistor is embedded, the flatness of the surface thereof is very poor. Therefore, the surface of the sacrificial layer 39 is planarized by using a spin on glass (SOG) method or a chemical mechanical polishing (CMP) method.

Subsequently, a first mask layer 41 for hard mask is formed on the sacrificial layer 39. The first mask layer 41 is deposited to have a thickness of about 500~1000Å using the method of silicate (SiO _2), PECVD (Plasma Enhanced CVD). Since the first mask layer 41 is deposited at a temperature of 400 ° C. or less, the active matrix 31 may be prevented from being thermally damaged.

After the first mask layer 41 for hard mask is deposited on the sacrificial layer 39, a second mask layer 43 is formed on the first mask layer 41. The second mask layer 43 is formed to have a thickness of about 500 to 1000 Å by using a spin coating method. After the second mask layer 43 is formed, the second mask layer 43 is patterned to expose a portion of the first mask layer 41 in which the drain 33 is formed. Subsequently, the first mask layer 41 is patterned by a dry etching method along the pattern of the second mask layer 43. In contrast to the wet etching method, the isotropic etching is performed, whereas in the dry etching method, the isotropic and anisotropic etching can be controlled to form a desired pattern.

Referring to FIG. 6B, after the first mask layer 41 is patterned as described above, the sacrificial layer 39 formed below is etched by using the first mask layer 41 as an etching mask. As a result, a portion in which the drain 33 is formed below the etch stop layer 37 is exposed. Conventionally, the sacrificial layer was patterned using a photoresist directly as a mask. In this case, the adhesion between the sacrificial layer and the photoresist is so poor that a part of the sacrificial layer to be protected by the photoresist is etched to generate an attack on the sacrificial layer, thereby making it impossible to accurately obtain a pattern having a desired shape. As a result, the thin films to be stacked in a subsequent process are unevenly stacked, resulting in a decrease in flatness of the actuator, and torsion and initial warpage occur even without an electric field applied. In the present invention, after applying the first mask layer 41 for hard mask to the upper portion of the sacrificial layer 39 using a silicate, the sacrificial layer 39 by using a second mask layer 43 composed of a photoresist It is possible to obtain an accurate pattern by improving the interfacial adhesion with

Further, the reason for not removing the patterned first mask layer 41 is that the first mask layer 41 is etched when the sacrificial layer 39 is etched using hydrogen fluoride (HF) vapor as a subsequent process. ) Can be removed together, so there is no need to remove it beforehand.

Referring to FIG. 6C, a membrane 45 is stacked on top of the exposed etch stop layer 37 and on top of the first mask layer 41. The membrane 45 is formed to have a thickness of about 0.1 to 1.0 탆 using low pressure chemical vapor deposition (LPCVD). Subsequently, a lower electrode 47, which is a signal electrode, is stacked on the membrane 45. The lower electrode 47 is formed by sputtering a metal such as platinum or tantalum (Ta) from 0.1 to 1. It is formed to have a thickness of about 0㎛. Subsequently, Iso-Cutting is performed so that the lower electrode 47 is separated for each pixel.

On top of the lower electrode 47, a strain layer 49 made of PZT or PLZT is stacked. The strained layer 49 is formed to have a thickness of about 0.1 to 1.0 mu m, preferably about 0.4 mu m using a sol-gel method, sputtering method, or chemical vapor deposition method. Subsequently, the strained layer 49 is subjected to heat treatment by a rapid thermal annealing (RTA) method to phase change. The deformation layer 49 is deformed by an electric field generated between the upper electrode 51 and the lower electrode 47.

The upper electrode 51 is stacked on one side of the strained layer 49. The upper electrode 51 uses a metal such as aluminum, silver, or platinum, by sputtering method, from 0.01 to 1. It is formed to have a thickness of about 0㎛. The upper electrode 51 is applied with a bias voltage as a common electrode. Therefore, when an image signal is applied to the lower electrode 47 and a bias voltage is applied to the upper electrode 51, an electric field is generated between the upper electrode 51 and the lower electrode 47. This deformation causes the deformation layer 49 to deform. Subsequently, the upper electrode 51, the strain layer 49, and the lower electrode 47 are sequentially etched and patterned from a top of the upper electrode 51 in a predetermined pixel shape.

Referring to FIG. 6D, via holes are sequentially etched from the other side of the strained layer 49, the lower electrode 47, the membrane 45, the etch stop layer 37, and the protective layer 35. (via hole) 55 is formed. The via hole 55 is vertically formed from the other side of the strained layer 49 to the drain 33. Subsequently, a via contact 57 is formed of a metal having excellent electrical conductivity such as tungsten (W), aluminum, or titanium (Ti) using a sputtering method. The via contact 57 electrically connects the drain 33 and the lower electrode 47. Therefore, the image signal is applied to the lower electrode 47 through the drain 33 and the via contact 57 from the transistor embedded in the active matrix 31. Subsequently, the membrane 45 is patterned into a predetermined pixel shape.

Referring to FIG. 6E, the first mask layer 41 and the sacrificial layer 39 are etched using hydrogen fluoride (HF) vapor to form an air gap 53. Then, a rinse and dry treatment is 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 using an active matrix 31. Is deposited at the bottom of the to form an ohmic contact (not shown). In addition, a bias (Tape Carrier Package) (not shown) bonding is applied to apply a bias voltage to a subsequent upper electrode 51, which is a common electrode, and an image signal to a lower electrode 47, which is a signal electrode. The active matrix 31 is cut to a predetermined thickness by using a conventional photolithography method. Subsequently, a photoresist layer (not shown) is formed on 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 using a dry etching method or a wet etching method, and the active matrix 31 is completely cut into a predetermined shape, and then the pad of the AMA panel and the pad of TCP are ACF (Anisotropic Conductive Film). (Not shown) to complete the manufacture of the thin film AMA module (module).

In the above-described thin film type optical path control device according to the present invention, the image signal transmitted through the pad of the TCP and the pad of the AMA panel is transmitted through the transistor, the drain 33 and the via contact 57 built in the active matrix 31. The lower electrode 47 is applied as a signal electrode. At the same time, a bias voltage is applied to the upper electrode 51, which is a common electrode, to generate an electric field between the upper electrode 51 and the lower electrode 47. The strained layer 49 between the upper electrode 51 and the lower electrode 47 causes deformation by this electric field. The strained layer 49 is contracted in a direction perpendicular to the electric field, and thus the actuator 32 including the strained layer 49 is bent at a predetermined angle. The upper electrode 51, which also functions as a mirror that reflects the light beam, is formed on the actuator 32 so that the upper electrode 51 is inclined together with the actuator 32. Accordingly, the upper electrode 51 reflects the light beam incident from the light source at a predetermined angle, and the reflected light flux passes through the slit to form an image on the screen.

In the method of manufacturing the thin film type optical path control device according to the present invention, when patterning the sacrificial layer, the sacrificial layer and the first mask layer for the hard mask made of silicate are laminated before using the photoresist as the second mask layer. The sacrificial layer can be accurately patterned by minimizing the attack of the sacrificial layer due to the poor interfacial adhesion between the masks. Accordingly, since the thin films to be laminated later may be uniformly stacked, twisting and initial tilting of the actuator may be prevented, and light reflection efficiency of the light beam incident from the light source may be constant. In addition, the first mask layer may be deposited at a temperature of 400 ° C. or less, thereby preventing the active matrix from being thermally damaged.

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

Claims (8)

Providing an active matrix having M × N transistors embedded therein and having a drain formed on one side thereof; Forming a sacrificial layer on top of the active matrix; Forming a first mask layer for a hard mask by using silicate (SiO ₂ ) on the sacrificial layer; Forming a second mask layer on the first mask layer; Patterning the sacrificial layer; Forming a membrane on top of the patterned sacrificial layer; Forming a lower electrode on the membrane; Forming a strained layer on the lower electrode; Forming an upper electrode on the strain layer; And And patterning the upper electrode, the strain layer, the lower electrode, and the membrane in sequence. The thin film type of claim 1, wherein the forming of the sacrificial layer is performed after forming a protective layer on the active matrix and the drain and forming an etch stop layer on the protective layer. Method of manufacturing the optical path control device. The method of claim 1, wherein the forming of the first mask layer is performed using a Plasma Enhanced Chemical Vapor Deposition (PECVD) method to have a thickness of 500 to 1000 GPa. The method of claim 1, wherein the forming of the first mask layer is performed at a temperature of 400 ° C. or less. The method of claim 1, wherein the forming of the second mask layer is performed by using a spin coating method using a photoresist. The method of claim 1, wherein the forming of the membrane comprises: patterning the first mask layer for the hard mask using the second mask layer, and using the patterned first mask layer as an etching mask. Method of manufacturing a thin film type optical path control device characterized in that it is carried out after the step of patterning. The method of claim 1, wherein the patterning of the membrane comprises: etching the strain layer, the lower electrode, and the membrane from the other side of the strain layer to form a via hole vertically from the strain layer to the drain, and And forming a via contact for electrically connecting the drain and the lower electrode in the via hole. The thin film type optical path of claim 1, wherein the patterning of the membrane further comprises simultaneously etching the sacrificial layer and the first mask layer by using hydrogen fluoride (HF) vapor. Method of manufacturing the regulating device.