KR19980054835A - Thin film type optical path control device and method for manufacturing the same that can prevent initial bending of actuator - Google Patents

Abstract

Disclosed are a thin film type optical path adjusting apparatus capable of preventing initial bending of an actuator and a method of manufacturing the same. The device includes an active matrix having M × N (M, N is an integer) transistors, a drain formed on one side thereof, and iii) one side contacting an upper portion of the active matrix, and the other side being interposed with an air gap. A membrane stacked in parallel with the active matrix and having a first support part and a second support part formed on both sides of the one side; ii) a lower electrode stacked on top of the membrane, iii) a strained layer stacked on top of the lower electrode; Iii) an upper electrode stacked on top of the strained layer, and an actuator formed on the active matrix. The apparatus can prevent the initial bending of the actuator by minimizing the stress generated in the horizontal direction by forming the first support and the second support on both sides in the vertical direction with respect to the actuator formed on the active matrix.

Description

Thin-film optical path control device capable of preventing the initial bending of the actuator and its manufacturing method

The present invention relates to Actuated Mirror Arrays (AMA), which is a thin film type optical path control device, and a method of manufacturing the same. More particularly, the present invention can prevent initial tilting of an actuator by forming supports on both sides of an actuator. It relates to a thin film type optical path control device and a method of manufacturing the same.

In general, an optical path adjusting device capable of forming an image by adjusting a light beam is classified into two types. 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), or a DMD (Deformable Mirror Device), AMA, etc. This corresponds to this. Although the CRT device has excellent image quality, the weight and volume of the device increases as the screen is enlarged, and the manufacturing cost thereof increases. In contrast, a liquid crystal display (LCD) has an advantage in that its optical structure is simple and can be formed thin, thereby reducing its weight and volume. However, the liquid crystal display (LCD) has a problem that the efficiency is lowered to have a light efficiency of 1 to 2% due to the polarization of the incident light beam, and the response speed of the liquid crystal material is slow and the inside is easily overheated.

Accordingly, an image display device such as a DMD or an AMA has been developed to solve the above problems. Currently, AMA devices can achieve 10% or more light efficiency, while DMD devices have about 5% light efficiency. In addition, the AMA device improves contrast to produce brighter and clearer images, and is not affected by the polarity of the incident luminous flux and does not affect the polarity of the reflected luminous flux. A schematic diagram of the engine system of AMA disclosed in this US Patent No. 5,126,836 (issued to Gregory Um) is shown in FIG.

As shown in FIG. 1, the light beams incident from the light source 1 are spectroscopically observed through the R, G, B (Red, Green, Blue) colorimeter while passing through the first slit 3 and the first lens 5. . The luminous flux spectra for R, G, and B are respectively reflected by the first mirror 7, the second mirror 9, and the third mirror 11, and are arranged in correspondence with the respective mirrors. 15) (17). The AMA elements 13, 15, and 17 formed for each of R, G, and B reflect the incident light beams by inclining the mirrors provided therein at a predetermined angle. At this time, the mirror is inclined according to the deformation of the active layer formed under the mirror. The light reflected from the AMA elements 13, 15, 17 passes through the second lens 19 and the second slit 21, and then is projected to the screen (not shown) by the projection lens 23. Projected to form an image.

In most cases, zinc oxide (ZnO) is used as a constituent material of the strained layer. However, it has recently been known that PZT (lead zirconate titanate, Pb (Zr, Ti) O ₃ ) has better piezoelectric properties than zinc oxide. The PZT is a complete solid solution (solid solution) of PbZrO ₃ and PbTiO ₃ high temperature in the crystal structure of the cubic crystal (cubic) of paraelectric phase inversion (paraelectric phase) in the presence, and is the normal temperature determined by the composition ratio of Zr and Ti structure orthorhombic It exists as an orthorhombic antiferroelectric phase, a rhombohedral ferroelectric phase, and a tetragonal ferroelectric phase.

A binary phase diagram of this PZT is shown in FIG. 2. Referring to FIG. 2, there is a tetragonal phase and a rhombohedral phase in a composition having a ratio of Zr and Ti of about 1: 1, and PZT is a phase boundary (MPB). It exhibits maximum dielectric and piezoelectric properties in the composition of MPB). The phase boundary is not located in a specific composition but is a region in which a tetragonal phase and a rhombohedral phase coexist over a relatively wide composition range, and the phase coexistent region ranges from 2 to 3 mol% to 15 mol% depending on the researcher. Are reported differently. Many theories such as thermodynamic stability, compositional fluctuation, and internal stress have been suggested as the causes of such coexistence. Currently, PZT thin films can be manufactured using various processes such as spin coating, chemical vapor deposition (CVD), sputtering, and the like.

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 (issued to Gregory Um et al.). The bulk optical path control device cuts a thin layer of multilayer ceramic, mounts a ceramic wafer having a metal electrode therein on an active matrix in which a transistor is built, and then processes it by sawing. This is done by installing a mirror. However, the bulk optical path control device has a problem in that high precision is required in design and manufacturing, and the response speed of the deformation layer is slow. Accordingly, a thin film type optical path control apparatus that can be manufactured using a semiconductor process has been developed.

The 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 membrane and its manufacturing method), filed by the applicant on September 24, 1996. . FIG. 3 is a plan view of the thin film type optical path adjusting device described in the preceding application, FIG. 4 is a cross-sectional view taken along line AA ′ of the device shown in FIG. 3, and FIGS. 5A to 5C are shown in FIG. 4. It is a manufacturing process diagram of one apparatus.

3 and 4, the thin film type optical path control apparatus includes an active matrix 41 having a drain 49 formed on one side thereof, and an actuator 43 formed on the active matrix 41.

The active matrix 41 may include a passivation layer 51 stacked on the active matrix 41 and a drain 49 and an etch stop layer stacked on the passivation layer 51. 53). M x N MOS transistors (not shown) are embedded in the active matrix 41.

One side of the actuator 43 is in contact with a portion in which the drain 49 is formed in the lower portion of the etch stop layer 53, and the other side thereof is parallel to the etch stop layer 53 through an air gap 55. The stacked membrane 57, the bottom electrode 61 stacked on the membrane 57, the strain layer 63 stacked on the lower electrode 61, and the strain layer 63. The upper electrode 65 stacked on one side of the top, the drain electrode from the other side of the deformation layer 63 through the lower electrode 61, the membrane 57, the etch stop layer 53 and the protective layer 51 A via hole 68 formed up to 49 and a via contact 69 formed so that the lower electrode 61 and the drain 49 are electrically connected to each other in the via hole 68. Include.

Referring to FIG. 3, one side of the membrane 57 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 membrane 57 has a rectangular protrusion that narrows stepwise toward the central portion corresponding to the concave portion. Therefore, the recessed portion of the membrane of the actuator adjacent to the recessed portion of the membrane 57 is fitted, and the rectangular projection is fitted to the recessed portion of the adjacent membrane.

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

5A to 5D show a manufacturing process diagram of the apparatus shown in FIG. 4. 5A to 5D, the same reference numerals are used for the same members as in FIG.

Referring to FIG. 5A, Phospho-Silicate Glass is formed on top of an active matrix 41 having M × N metal oxide semiconductor (MOS) transistors (not shown) and a drain 49 formed on one side thereof. : A protective layer 51 composed of PSG is laminated. The protective layer 51 is formed to have a thickness of about 1.0 to 2.0 µm using the chemical vapor deposition (CVD) method. The protective layer 51 protects the active matrix 41 during subsequent processing.

An etch stop layer 53 made of nitride is stacked on the passivation layer 51. The etch stop layer 53 is formed to have a thickness of about 1000 to 2000 kPa using a low pressure chemical vapor deposition (LPCVD) method. The etch stop layer 53 prevents the protective layer 51 and the active matrix 41 from being etched and damaged during the subsequent etching process. A sacrificial layer 56 is stacked on the etch stop layer 53. The sacrificial layer 56 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 2.0 μm using the Atmospheric Pressure Vapor Deposition (APCVD) method. Form. In this case, since the sacrificial layer 56 covers the upper portion of the active matrix 41 in which the transistors are embedded, the flatness of the surface thereof is very poor. Accordingly, the surface of the sacrificial layer 56 is planarized by using a spin on galss (SOG) method or a chemical mechanical polishing (CMP) method. Subsequently, a portion of the sacrificial layer 56 in which the drain 49 is formed below is etched to expose a portion of the etch stop layer 53.

Referring to FIG. 5B, the membrane 57 is stacked on the exposed etch stop layer 53 and on the sacrificial layer 56 at a thickness of about 0.01 to 1.0 μm. The membrane 57 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 57 made of silicon carbide is annealed at a temperature of 600 ° C. or less to control the stress in the membrane 57.

A lower electrode 61 made of a metal such as platinum (Pt) or tantalum (Ta) is stacked on the membrane 57. The lower electrode 61 is formed to have a thickness of about 500 to 2000 mW using a sputtering method. An image signal generated from a transistor embedded in the active matrix 41 is applied to the lower electrode 61, which is a signal electrode, through the drain 49 and the via contact 69. The lower electrode 61 is etched and patterned to separate the pixels.

Referring to FIG. 5C, a strain layer 63 including PZT or PLZT is stacked on the lower electrode 61. The strained layer 63 is formed to have a thickness of about 0. 1 to 1.0 μm, preferably about 0.4 μm using a Sol-Gel method, and then rapid thermal annealing. : It heat-processes by a RTA method and makes a phase change. The strained layer 63 causes deformation due to an electric field generated between the upper electrode 65 and the lower electrode 61. The upper electrode 67 is stacked on one side of the strained layer 63. The upper electrode 67 is formed of a metal having excellent electrical conductivity and reflectivity, such as aluminum (Al) or platinum, to have a thickness of about 500 to 2000 kW using a sputtering method. A bias voltage is applied to the upper electrode 57, which is a common electrode, to generate an electric field between the lower electrode 61 and the upper electrode 57. In addition, the upper electrode 57 also functions as a mirror that reflects the light beam incident from the light source. Subsequently, the upper electrode 65 is patterned to form a stripe 67 at the center thereof. The stripe 67 uniformly operates the upper electrode 65 to prevent diffuse reflection of the incident light beam.

Referring to FIG. 5D, after the upper electrode 65 is patterned into a predetermined shape, the strained layer 63, the lower electrode 61, and the membrane (from the upper side of the strained layer 63 to the upper portion of the drain 49). 57, the etch stop layer 53, and the protective layer 51 are sequentially etched to form a via hole 68 vertically from the strained layer 63 to the drain 49. Subsequently, a via contact 69 is formed to electrically connect the drain 49 and the lower electrode 61 by sputtering a metal such as tungsten (W), platinum, or titanium (Ti). Thus, the via contact 69 is formed vertically from the lower electrode 61 to the top of the drain 49 in the via hole 68. Therefore, the image signal generated from the transistor embedded in the active matrix 41 is applied to the lower electrode 61 through the drain 49 and the via contact 69. Subsequently, the strained layer 63, the lower electrode 61, and the membrane 57 are sequentially patterned, and then the sacrificial layer 56 is etched with hydrogen fluoride (HF) vapor to form an air gap 55. do. After completing the thin-film AMA device as described above, platinum-tantalum (Pt-Ta) is deposited on the lower end of the active matrix 41 using a sputtering method to form an ohmic contact (not shown). Subsequently, after coating a photo resist (not shown) on the active matrix 41, a bias voltage is applied to the upper electrode 65, which is a subsequent common electrode, and a lower electrode, which is a signal electrode. The active matrix 41 is cut in preparation for TCP (Tape Carrier Package) (not shown) bonding for applying an image signal to 61. At this time, the active matrix 41 is cut out to a thickness of about ⅓ for the subsequent process. Subsequently, the pad portion of the AMA panel is etched using a dry etching method to expose a pad (not shown) of the AMA panel required for TCP bonding. After the active matrix 41 in which the thin film type AMA element is formed is completely cut into a predetermined shape, the pad of the AMA panel and the TCP are connected to complete the manufacture of the thin film type AMA module.

However, in the thin film type optical path adjusting device described in the preceding application, since the support part is formed only on one side of the actuator, there is a problem that the initial bending of the actuator is large. That is, after the portion of the sacrificial layer is patterned to form the position where the support is to be formed, the thickness of the layers of the support portion is thicker than the thickness of the driving portion toward the support portion during lamination of the membrane, the lower electrode, the deformation portion and the upper electrode. The stress that attracts the driving unit is generated, and due to such stress, there is a problem that the initial bending of the entire actuator is large toward the support unit.

Accordingly, an object of the present invention is to minimize the stress generated in the horizontal direction by forming support portions on both sides in the vertical direction with respect to the actuator formed on the active matrix to prevent the initial bending of the actuator due to the stress generated in the horizontal direction The present invention provides a thin film type optical path control device and a method of manufacturing the same.

1 is a schematic diagram of an engine system of a conventional optical path control apparatus.

2 is a binary state diagram of the PZT.

3 is a plan view of a thin film-type optical path control device previously applied by the present applicant.

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

5A to 5D are manufacturing process diagrams of the apparatus shown in FIG. 4.

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

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

FIG. 8 is a cross-sectional view taken along line C′C ′ of the apparatus shown in FIG. 6.

9A to 12B are manufacturing process diagrams of the apparatus shown in FIGS. 7 and 8.

<Explanation of symbols for main parts of drawing>

100: active matrix 105: drain

110: protective layer 115: etch stop layer

120: sacrificial layer 125: air gap

130 membrane 130a first support part

130b: second support 135: lower electrode

140: strained layer 145: upper electrode

150: beer hall 155: beer contact

160: mirror post 165: mirror

170: actuator

The present invention to achieve the above object,

An active matrix in which M × N (M and N are integer) transistors are formed and a drain is formed on one side; And

Iii) a membrane in which one side is in contact with an upper portion of the active matrix and the other side is stacked in parallel with the active matrix via an air gap, and a first support and a second support are formed at both sides of one side, and ii) an upper portion of the membrane. A thin film type optical path control device comprising: a lower electrode stacked on the lower electrode; iii) a strained layer stacked on top of the lower electrode; and iii) an upper electrode stacked on the upper portion of the strained layer. To provide.

In addition, the present invention to achieve the above object,

Providing an active matrix having M × N (M, N is an integer) transistors formed therein and having a drain formed on one side thereof; And

Iii) forming a membrane on top of the active matrix, ii) patterning the membrane to form a first support and a second support, iii) forming a bottom electrode on top of the patterned membrane, iii) A thin film type optical path control device comprising the step of forming an actuator on top of the active matrix, comprising the step of forming a strained layer on top of the lower electrode and iii) forming an upper electrode on the top of the strained layer. It provides a method for producing.

In the thin film type optical path adjusting device according to the present invention, a bias voltage is applied to the upper electrode through a pad of TCP and a pad of an AMA panel. At the same time, the image signal transmitted through the pad of the TCP and the pad of the AMA panel 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 mirror reflecting the light beam is inclined with the actuator because it is formed on the actuator through the mirror post. Accordingly, the mirror 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.

The thin film type optical path adjusting device and the method of manufacturing the same according to the present invention minimize the stress generated in the horizontal direction by forming first and second support parts on both sides in the vertical direction with respect to the actuator formed on the active matrix to prevent the initial bending of the actuator. can do. Therefore, it is possible to improve the light efficiency of the light beam incident from the light source and reflected by the mirror formed on the actuator according to the driving angle of the actuator.

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

6 is a plan view showing a thin film type optical path control device according to the present invention, Figure 7 is a cross-sectional view taken along the line BB 'of the device shown in Figure 6, Figure 8 is a CC of the device shown in Figure 6 A cross-sectional view taken along the line ′ is shown, and FIGS. 9A to 12B show a manufacturing process diagram of the apparatus shown in FIGS. 7 and 8. In Figs. 9A to 12B, the same reference numerals are used for the same members as Figs. 7 and 8.

6 and 7, the thin film type optical path adjusting apparatus according to the present invention has an active MxN (M, N is an integer) transistor (not shown) embedded therein and a drain 105 formed on one side thereof. An actuator 170 is formed on the matrix 100 and the active matrix 100. The active matrix 100 includes a protective layer 110 stacked on the active matrix 100 and a drain 105 and an etch stop layer 115 stacked on the protective layer 110.

The actuator 170 includes a membrane 130 stacked in parallel with the etch stop layer 115 via an air gap 125, a lower electrode 135 stacked on the membrane 130, and a lower electrode 135. An active layer 140 stacked on top of the upper layer includes an upper electrode 145 stacked on top of the deformation layer 140. A mirror post 160 is formed on one side of the upper electrode 145. The mirror 165 is formed to cover the upper electrode 145 in parallel with the upper electrode 145 and the lower side of one side is in contact with the mirror post 160.

Referring to FIG. 8, a first support part 130a and a second support part 130b are formed at one side of the membrane 130 in a direction perpendicular to the actuator 170 formed on the active matrix 100. Each of the first support part 130a and the second support part 130b is in contact with the etch stop layer 115, and a central part thereof has a quadrangular shape and protrudes upward through the air gap 125. The first support part 130a of the membrane 130 is formed through the strained layer 140, the lower electrode 135, the first support part 130a of the membrane 130, the etch stop layer 115, and the protective layer 110. The via hole 150 is vertically formed to the drain 105, and a via contact 135 is formed in the via hole 150 to electrically connect the lower electrode 135 and the drain 105.

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

FIG. 9A illustrates a cross-sectional view in a horizontal direction with respect to the actuator 170 formed on the active matrix 100 patterned on the sacrificial layer 120, and FIG. 9B illustrates the active matrix 100 patterned on the sacrificial layer 120. It shows the cross-sectional view in the vertical direction with respect to the actuator 170 formed on. 9A and 9B, M × N (M and N are integers) MOS transistors (not shown) are built in a semiconductor memory device, which has a feature of increasing the degree of integration and is widely used in large scale integrated circuits. An active matrix 100 having a drain 105 formed on one surface thereof is provided. Preferably, the active matrix 100 is made of a semiconductor such as silicon (Si). Next, the protective layer 110 is deposited on the active matrix 100 to have a thickness of about 0.01 to 1.0 탆 using a chemical vapor deposition (CVD) method. Preferably, the protective layer 110 is made of in-silicate glass (PSG), and prevents the active matrix 100 from being damaged when the surface of the sacrificial layer 120 formed in a subsequent process is planarized.

Next, an etch stop layer 115 made of nitride is stacked on the protective layer 110 to a thickness of about 1000 to 2000 kPa. The etch stop layer 115 is deposited using a low pressure chemical vapor deposition (LPCVD) process for depositing a thin film. That is, the etch stop layer 115 is formed by depositing nitride on the protective layer 110 using a chemical reaction by thermal energy in a low pressure reaction vessel. The etch stop layer 115 serves to prevent the active matrix 100 and the protective layer 110 from being etched and damaged when the sacrificial layer 120 is etched.

Subsequently, the sacrificial layer 120 is laminated on the etch stop layer 115. The sacrificial layer 120 functions to facilitate lamination to form the actuator 170, and is removed by hydrogen fluoride (HF) vapor after the formation of the actuator 170 is completed. The sacrificial layer 120 is formed of phosphorus silicate glass (PSG) having a high phosphorus (P) concentration to a thickness of about 0.5 to about 2.0 μm using an atmospheric chemical vapor deposition (APCVD) process. That is, the sacrificial layer 120 is deposited using a chemical reaction by thermal energy in a reaction vessel under atmospheric pressure. In this case, since the sacrificial layer 120 covers the surface of the active matrix 100 in which the transistors are embedded, the flatness of the surface is very poor. Accordingly, the surface of the sacrificial layer 120 is planarized by using spin on glass (SOG) made of siloxane or silicate mixed with an alcohol-based solvent, or by using a chemical mechanical polishing (CMP) process.

Next, the sacrificial layer 120 is patterned using a dry etching process or a wet etching process to form a position at which the first support 130a and the second support 130b are to be formed. That is, for example, the sacrificial layer 120 is etched using an etching solution such as hydrogen fluoride (HF), or the sacrificial layer 120 is etched using a plasma or an ion beam. As shown in FIG. 9B, the first support portion 130a is formed at an upper portion of the etch stop layer 115 having the drain 105 formed thereon, and the second support portion 130b is formed at an adjacent portion thereof. Make a location.

FIG. 10A illustrates the cross-sectional view in the horizontal direction patterned membrane 130, and FIG. 10B illustrates the cross-sectional view in the vertical direction patterned membrane 130. 10A and 10B, the membrane 130 made of nitride is laminated to a thickness of about 0.01 to 1.0 mu m. The membrane 130 is deposited using a low pressure chemical vapor deposition (LPCVD) process similar to the method of forming the etch stop layer 115 made of nitride. At this time, the stress inside the membrane 130 is controlled by forming the membrane 130 while changing the ratio of the reactive gas with time in the low pressure reaction vessel.

Subsequently, after applying a photoresist layer (not shown) on the membrane 130, the membrane 130 is patterned to form a first support 130a and a second support as shown in FIG. 10B. 130b is formed. The first support part 130a is in contact with the etch stop layer 115 having a drain 105 formed therein, and the second support part 130b is in contact with the first support part 130a in the vertical direction. Contact with Conventionally, the support portion of the actuator is formed only in the horizontal direction with respect to the actuator formed on the active matrix so that the thickness of each layer on the support side is thicker than the thickness on the drive side, so that a stress that pulls toward the support portion is generated, which causes the initial stage of the actuator. The warpage was large. However, in the present invention, as described above, the first support 130a and the second support 130b are formed on both sides of the actuator 170 in a direction perpendicular to the actuator 170 formed on the active matrix 100. . Therefore, the thickness of the driving unit can be constant, and the stress generated in the horizontal direction can be minimized to prevent the actuator 170 from being initially bent.

FIG. 11A illustrates a cross-sectional view in the horizontal direction in which the upper electrode 145 is stacked, and FIG. 11B illustrates a cross-sectional view in the vertical direction in which the upper electrode 145 is stacked. Referring to FIGS. 11A and 11B, platinum (Pt) or platinum (Pt) -tantalum (Ta) of about 0.01 to 1.0 μm using a sputtering process on the patterned membrane 130. By depositing at a thickness, the lower electrode 135 as a signal electrode is formed. After the lower electrode 135 is formed, an iso-cut is performed to separate the lower electrode 135 for each pixel. Subsequently, piezoelectric ceramics or electrostrictive ceramics are laminated using a sol-gel method to form a strained layer 140 as a piezoelectric layer. For example, BaTiO ₃ , PZT (Pb (Zr, Ti) O ₃ ), which is a piezoelectric ceramic, or PLZT ((Pb, La) (Zr, Ti) O ₃ ) is deposited, or Pb (Mg, Nb) O ₃ is deposited. Preferably, PZT (Pb (Zr, Ti) O ₃ ) is laminated to a thickness of about 0.1 to 1.0 탆 to form a strained layer 140. Next, the strained layer 140 is subjected to heat treatment using a rapid heat treatment (RTA) process to cause phase change. Subsequently, aluminum (Al) or platinum (Pt) is sputtered on the strained layer 140. As a result, the upper electrode 145, which is a common electrode having a thickness of about 0.01 to 1.0 mu m, is formed. Subsequently, the upper electrode 145, the strained layer 140, and the lower electrode 135 are sequentially patterned in a pixel shape. That is, after forming a photoresist layer (not shown) resistant to the material to be etched on the upper electrode 145, the upper electrode 145 is patterned. Subsequently, after forming a photoresist protective layer (not shown) on the upper electrode 145 and the strained layer 140, the strained layer 140 is patterned. In this manner, the lower electrode 135 is also patterned into a predetermined pixel shape.

FIG. 12A illustrates a cross-sectional view in the horizontal direction in which the mirror 165 is formed, and FIG. 12B illustrates a cross-sectional view in the vertical direction in which the via contact 155 is formed. Referring to FIG. 12B, after the patterning is completed as described above, the strained layer 140 from one side of the strained layer 140 on the first support 130a to the top of the drain 105 using a photolithography process. The via hole 150 is formed by sequentially etching the lower electrode 135, the membrane 130, the etch stop layer 115, and the protective layer 110. When the etching is completed and the via hole 150 is formed, a conductive material is filled in the via hole 150 using a sputtering process. That is, tungsten (W) or titanium (Ti) having good conductivity is filled in the via hole 150 using a metal sputtering process. As such, the via contact 150 is filled with the conductive material to form the via contact 155 to electrically connect the drain 105 and the lower electrode 135. Referring to FIG. 12A, after forming the via contact 155 as described above, a photoresist layer (not shown) is coated on the entire surface of the resultant product.

Subsequently, one side of the upper electrode 145 is patterned to expose the mirror post 160. Subsequently, after sputtering a metal such as silver, aluminum, or platinum on one side of the exposed upper electrode 145 and on the photoresist layer, patterning is performed to simultaneously mirror and mirror 165 and mirror post 160. Form. The mirror 165 is formed to have a thickness of about 500 ~ 2000Å. After etching the photoresist layer, the sacrificial layer 120 is removed using hydrogen fluoride (HF) vapor. Then, rinsing and drying are performed to remove the remaining etching solution. As such, when the sacrificial layer 120 is removed, the air gap 125 is formed.

After completing the M × N thin-film AMA devices as described above, platinum-tantalum (Pt-Ta) is deposited on the bottom of the active matrix 100 using a sputtering method to form a resistive 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 145 which is a common electrode and an image signal to a lower electrode 135 which is a signal electrode. To cut the active matrix 100 using a conventional photolithography method. In this case, the active matrix 100 is prepared in preparation for the subsequent process. Only cut to thickness. Subsequently, after forming a photoresist layer (not shown) on the pad (not shown) of the AMA panel to have a sufficient height in preparation for TCP bonding, a portion of the photoresist layer below which the pad is formed. Pattern to expose the pads of the AMA panel. After that, the photoresist layer is removed. Subsequently, the pad of the AMA panel and the pad of TCP are connected to complete the manufacture of the thin film AMA module.

In the above-described thin film type optical path control device according to the present invention, a bias voltage is applied to the upper electrode 145 through a pad of TCP and a pad of an AMA panel. At the same time, the image signal transmitted through the pad of the TCP and the pad of the AMA panel is applied to the lower electrode 135 through the transistor, the drain 105 and the via contact 155 embedded in the active matrix 100. Accordingly, an electric field is generated between the upper electrode 145 and the lower electrode 135, and the strained layer 140 between the upper electrode 145 and the lower electrode 135 causes deformation by the electric field. The strained layer 140 contracts in a direction perpendicular to the electric field, and thus the actuator 170 including the strained layer 140 is bent at a predetermined angle. Since the mirror 165 reflecting the light beam is formed on the actuator 170 through the mirror post 160, the mirror 165 is inclined together with the actuator 170. Accordingly, the mirror 165 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.

In the thin film type optical path adjusting device described in the prior application, the thickness of each layer on the support side is greater than the thickness of each layer on the driving side because the support portion of the actuator is formed only in one position under the actuator in the horizontal direction with respect to the actuator formed on the active matrix. Thickness caused stress to pull towards the support. Due to the stress generated in the horizontal direction with respect to the actuator formed on the active matrix, the initial bending of the actuator is large, resulting in a problem of lowering the light efficiency of the luminous flux incident from the light source. However, in the present invention, by forming the first support and the second support on both sides in the vertical direction with respect to the actuator formed on the active matrix, it is possible to minimize the stress generated in the horizontal direction to prevent the initial bending of the actuator. As a result, it is possible to improve the light efficiency of the light beam incident from the light source and reflected by the mirror on the actuator according to the driving angle of the actuator.

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

Claims (10)

An active matrix 100 having M × N (M, N is an integer) transistors and a drain 105 formed on one side thereof; And Iii) one side is in contact with the upper portion of the active matrix 100 and the other side is stacked in parallel with the active matrix 100 via the air gap 125, the first support portion 130a and the first side portion on both sides 2, a membrane 130 having a supporting portion 130b, ii) a lower electrode 135 stacked on the membrane 130, iii) a strained layer 140 stacked on the lower electrode 135, and A thin film type optical path control device including an upper electrode (145) stacked on top of the deforming layer (140), and an actuator (170) formed on the active matrix (100). The active matrix 100 of claim 1, wherein the active matrix 100 includes a protective layer 110 stacked on the active matrix 100 and the drain 105 and an etch stop layer stacked on the protective layer 110. Thin film type optical path control device characterized in that it further comprises. 3. The method of claim 2, wherein the first support part 130a of the membrane 130 is formed from the strained layer 140, the lower electrode 135, the membrane 130, and the etching from the other side of the strained layer 140. The via hole 150 vertically formed to the upper portion of the drain 105 through the prevention layer 115 and the via contact 155 connecting the lower electrode 135 and the drain 105 in the via hole 150. Thin film type optical path control device further comprising a. The method of claim 1, wherein the actuator 170 is to contact the mirror post 160 formed on one side of the upper electrode 145 and the lower side of the mirror post 160 to cover the upper electrode 145. Thin film type optical path control device further comprises a mirror (165) formed. The thin film type optical path of claim 4, wherein the mirror 165 has a thickness of 1000 to 2000 μs using silver, aluminum, or platinum, and the mirror post 160 is formed of the same material as the mirror. Regulator. The method of claim 1, wherein the first support portion 130a and the second support portion 130b of the membrane 130 are arranged side by side in a direction perpendicular to the actuator 170 formed on the active matrix 100. Thin film type optical path control device, characterized in that. Providing an active matrix having M × N (M, N is an integer) transistors formed therein and having a drain formed on one side thereof; And Iii) forming a membrane on top of the active matrix, ii) patterning the membrane to form a first support and a second support, iii) forming a bottom electrode on top of the patterned membrane, iii) A thin film type optical path control device comprising the step of forming an actuator on top of the active matrix, comprising the step of forming a strained layer on top of the lower electrode and iii) forming an upper electrode on the top of the strained layer. Method of preparation. The method of claim 7, wherein the forming of the membrane comprises: i) forming a protective layer on top of the active matrix and the drain, ii) forming an etch stop layer on top of the protective layer; Forming a sacrificial layer on top of the barrier layer, and iii) etching a portion of the sacrificial layer with a drain formed below and an adjacent portion thereof in a direction perpendicular to an actuator formed on the active matrix to remove a portion of the etch barrier layer. A method of manufacturing a thin film type optical path control device, characterized in that it is carried out after the step of exposing. The method of claim 7, wherein the forming of the first support of the membrane comprises: forming a via hole vertically formed from the strained layer to the upper portion of the drain through the lower electrode, the first support of the membrane; And forming a via contact connecting the lower electrode and the drain in a hole. The method of claim 7, wherein the forming of the actuator comprises: applying a photoresist on the upper electrode, and patterning the photoresist so that one side of the upper electrode is exposed, the exposed upper electrode and the Sputtering silver, aluminum, or platinum on top of the photoresist, and patterning the sputtered silver, aluminum, or platinum to form a mirror post and a mirror simultaneously. Method of preparation.