KR100225587B1 - Thin film type actuated mirror arrays - Google Patents

Abstract

A thin film type optical path control device is disclosed. The device includes an active matrix having M × N (M, N is an integer) transistors formed thereon and a drain pad formed on one side thereof, respectively iii) a membrane formed on top of the active matrix, ii) formed on top of the membrane, respectively. A lower electrode, iii) a deformable layer each formed on an upper portion of the lower electrode, and iii) a plurality of actuating parts including upper electrodes formed on an upper portion of the deformable layer and driving in the same direction, and an upper portion of the actuating parts. It includes a mirror formed in. According to the above apparatus, since the actuators are formed to avoid the portion where the drain pad is formed on the active matrix and then the image signal is applied from the drain pad to the lower electrodes through the metal line, the transistor embedded in the active matrix is damaged. Wearing can be minimized. In addition, by forming a common electrode line thickly on one side of the actuating portions, it is possible to minimize the voltage drop inside the common electrode line to apply sufficient voltage to the upper electrodes to cause deformation of the strain layers. In addition, by applying the second sacrificial layer and supporting the mirror through the plurality of support parts, the horizontality of the mirror may be improved.

Description

Thin Film Type Light Path Regulator

The present invention relates to an Actuated Mirror Array (AMA), which is a thin film type optical path control device, and more particularly, stabilizes electrical wiring of an upper electrode and a lower electrode, and improves the horizontal level of a mirror by forming a mirror through a plurality of supports. The present invention relates to a thin film type optical path control device that improves light efficiency and can prevent damage to a transistor embedded in an active matrix.

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 deformable mirror device (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, resulting in brighter and clearer images, and is not affected by the polarity of the incident luminous flux and does not affect the polarity of the 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 deformation portion formed in the lower portion of 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.

Zinc oxide (ZnO) is generally used as a constituent material of the deformable portion. 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 manufacture and 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. The thin film type optical path control device is disclosed in Korean Patent Application No. 96-64440 (name of the invention: thin film type optical path control device) filed by the applicant to the Korean Intellectual Property Office.

FIG. 3 shows a plan view of the thin film type optical path adjusting device described in the preceding application, FIG. 4 shows a cross-sectional view taken along line AA ′ of the device shown in FIG. 3, and FIGS. 5A to 5F are shown in FIG. 4. It is a manufacturing process diagram of one apparatus.

Referring to FIG. 3, the thin film type optical path adjusting device includes an active matrix 31 and an actuator 33. The active matrix 31 having M x N (M, N is an integer) internal metal oxide semiconductor (MOS) transistor (not shown) and having a drain 32 formed on one surface thereof is the active matrix 31. A protective layer 35 stacked on the matrix 31 and the drain 32 and an etch stop layer 37 stacked on the protective layer 35 are included.

One side of the actuator 33 is in contact with a portion in which the drain 32 is formed in the lower portion of the etch stop layer 37, and the other side of the actuator 33 passes through a first air gap 39. On the membrane 41 stacked in parallel with the lower electrode 43 stacked on the membrane 41, the strained layer 45 stacked on the lower electrode 43, and one side of the strained layer 45. Vias vertically formed from the other side of the stacked upper electrode 47 and the strained layer 45 to the drain 32 through the lower electrode 43, the membrane 41, the etch stop layer 37, and the protective layer 35. The via 48 includes a via contact 49 formed in the via hole 48 so that the lower electrode 43 and the drain 32 are electrically connected to each other.

In addition, a mirror 53 having a '-' shape is formed horizontally with the upper electrode 47 through a second air gap 51 having a support part contacting an upper end of one side of the upper electrode 47.

Hereinafter, a method of manufacturing the thin film type optical path adjusting device will be described.

Referring to FIG. 5A, Phospho-Silicate is formed on top of an active matrix 31 in which M × N (M and N are integers) transistors (not shown) are formed and a drain 32 is formed on one side. A protective layer 35 made of Glass: PSG is laminated. The protective layer 35 is formed to have a thickness of about 1.0 μm using a chemical vapor deposition (CVD) method. The protective layer 35 protects the active matrix 31 during subsequent processing.

An etch stop layer 37 made of nitride is stacked on the passivation layer 35. The etch stop layer 37 is formed to have a thickness of about 0.01 to 1.0 탆 using a low pressure chemical vapor deposition (LPCVD) method. The etch stop layer 37 prevents the protective layer 35, the active matrix 31, and the like from being etched during the subsequent etching process. The first sacrificial layer 38 is stacked on the etch stop layer 37. The first sacrificial layer 38 is formed of phosphorous silicate glass (PSG) having a high concentration of phosphorus (PG) by using atmospheric pressure chemical vapor deposition (Atmospheric Pressure CVD: APCVD) method. Form to have. In this case, since the first sacrificial layer 38 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 first sacrificial layer 38 is planarized by using a spin on glass (SOG) method or a chemical mechanical polishing (CMP) method. Subsequently, a portion of the first sacrificial layer 38 in which the drain 32 is formed is etched to expose a portion of the etch stop layer 37 to form a position where the support portion of the actuator 33 is to be formed.

Referring to FIG. 5B, the membrane 41 is stacked on the exposed etch stop layer 37 and on the first sacrificial layer 38 to a thickness of about 0.01 to 1.0 μm. The membrane 41 is formed using a low pressure chemical vapor deposition (LPCVD) method. At this time, the membrane 41 is formed while varying the ratio of the reaction gas in the low pressure reaction vessel to control the stress in the membrane 41. A lower electrode 43 made of metal such as platinum or platinum-tantalum (Pt-Ta) is stacked on the membrane 41. The lower electrode 43 is formed to have a thickness of about 0.01 to 1.0 탆 using the sputtering method. An image signal is applied to the lower electrode 43, which is a signal electrode, through the drain 32 and the via contact 49 from a transistor embedded in the active matrix 31.

A strained layer 45 formed of PZT or PLZT is stacked on the lower electrode 43. The strained layer 45 is formed so as to have a thickness of about 0.1 to 1.0 탆, preferably about 0.4 탆 using a sol-gel or chemical vapor deposition method (CVD). After that, heat treatment is performed by rapid thermal annealing (RTA) to cause phase shift. The strained layer 45 is deformed by an electric field generated between the upper electrode 47 as the common electrode and the lower electrode 43 as the signal electrode. The upper electrode 47 is stacked on one side of the strained layer 45. The upper electrode 47 is formed of a metal having excellent electrical conductivity such as aluminum or platinum so as to have a thickness of about 0.01 to 1.0 탆 using a sputtering method. A bias voltage is applied to the upper electrode 47, which is a common electrode, to generate an electric field between the lower electrode 43 and the upper electrode 47.

Referring to FIG. 5C, after the upper electrode 47 is patterned into a predetermined shape, the strained layer 45, the lower electrode 43, and the membrane from the other upper portion of the strained layer 45 to the upper portion of the drain 32 are formed. 41, the etch stop layer 37, and the protective layer 35 are sequentially etched to form the via holes 48 vertically from the strained layer 45 to the drain 32. Subsequently, a via contact 49 is formed to electrically connect the drain 32 and the lower electrode 43 by sputtering a metal such as tungsten, platinum, or titanium. Thus, the via contact 49 is formed vertically from the lower electrode 43 to the top of the drain 32 in the via hole 48. Therefore, the image signal is applied to the lower electrode 43 through the drain 32 and the via contact 49 from the transistor embedded in the active matrix 31. Subsequently, a metal such as chromium (Cr), copper (Cu), gold (Au), or the like is deposited on the bottom of the active matrix 31 by evaporation or sputtering to form an ohmic contact (not shown). Not formed). After coating a photoresist (not shown) on the active matrix 31, a bias voltage is applied to the upper electrode 47, which is a subsequent common electrode, and an image signal is applied to the lower electrode 43, which is a signal electrode. The active matrix 31 is cut in preparation for TCP (Tape Carrier Package) bonding for application. At this time, the active matrix 31 is cut out only to a predetermined thickness 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. Subsequently, the strained layer 45, the lower electrode 43, and the membrane 41 are sequentially patterned, and then the first sacrificial layer 38 is etched with hydrofluoric acid (HF) vapor to form the first air gap 39. By forming the actuator 33 is completed.

Referring to FIG. 5D, after forming the first air gap 39 as described above, the second sacrificial layer 50 is formed on the entire surface of the resultant. The second sacrificial layer 50 serves to facilitate mounting of the mirror 53 and to improve the horizontality of the mirror 53, and is removed after the mirror 53 is mounted. Preferably, the second sacrificial layer 50 is formed by spin coating a photoresist made of a polymer having good fluidity, and the like, based on the upper electrode 47 while completely filling the first air gap 39. Apply to have a certain thickness. As such, when the second sacrificial layer 50 is applied to the entire surface of the resultant formed actuator 33, the second sacrificial layer 50 is completely filled in the first air gap 39 to form a flat surface.

Referring to FIG. 5E, after forming the second sacrificial layer 50 as described above, the upper electrode 47 is patterned by patterning the second sacrificial layer 50 using a photoresist (not shown) as a mask. On one side of the upper portion of the mirror 53 is formed to make a support. Thus, the upper portion of one side of the upper electrode 47 is exposed. Subsequently, aluminum (Al) or silver (Ag) having good reflectivity was added to the upper portion of the second sacrificial layer 50 and the exposed upper electrode 47 on which the supporting portion was formed, in a range of 0.1 to 1.0 µm. The mirror 53 is formed by depositing to a thickness of a degree. Preferably, the mirror 53 has a '-' shape, the support of one side is in contact with the upper electrode 47, the other side is mounted in parallel to the upper electrode 47.

Referring to FIG. 5F, after forming the mirror 53 as described above, the second sacrificial layer 50 is removed with an oxygen plasma (O ₂ plasma) to separate the pixels, and a rinsing and drying process is performed. Perform As a result, the second air gap 51 is formed between the mirror 53 and the upper electrode 47, thereby completing the complete actuator 33 on which the mirror 53 is mounted.

After the active matrix 31 in which the thin film AMA element is formed is completely cut into a predetermined shape as described above, the pad and TCP of the AMA panel are connected to complete the manufacture of the thin film AMA module.

In the above-described thin film type optical path adjusting device, an image signal voltage is applied to the lower electrode 43, which is a signal electrode, and a bias voltage is applied to the upper electrode 47, which is a common electrode, so that the upper electrode 47 and the lower electrode ( An electric field is generated between 43). The strained layer 45 between the upper electrode 47 and the lower electrode 43 causes deformation by the electric field, and the strained layer 45 contracts in a direction perpendicular to the electric field. Accordingly, the actuator 33 including the membrane 41 is bent at a predetermined angle, and the mirror 53 mounted on the upper electrode 47 of the actuator 33 is deformed by the curved upper electrode 47. The axis is moved and tilted to reflect the light beam incident from the light source. The light beam reflected by the mirror 53 is projected onto the screen through the slit, thereby forming an image.

However, in the thin film type optical path adjusting device, since only a part of the upper electrode is driven as a mirror to reflect the light beam, the reflection angle of the incident light beam is small and the light efficiency is inferior. In addition, since the common electrode line passing through the rear surface of the pixel for applying the voltage to the upper electrode is very thin, the internal resistance is high, resulting in a voltage drop, and thus a sufficient voltage may not be applied to the upper electrode. Moreover, since via contacts are formed directly over the drain, there is a high possibility that transistors embedded in the active matrix will be directly affected by the subsequent process and be damaged.

Accordingly, an object of the present invention is to coat the common electrode wire on one side of the actuator with a mirror mounted thereon to prevent the voltage drop due to the resistance therein and to avoid the upper part of the drain pad, thereby forming the actuator. The present invention provides a thin film type optical path control device that stabilizes electrical wiring of an electrode and a lower electrode and prevents damage to a transistor embedded in an active matrix.

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 adjusting device described in the applicant's prior application.

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

5A to 5F 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.

7 is a perspective view of the apparatus shown in FIG. 6.

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

FIG. 9 is a cross-sectional view taken along line C′C ′ of the apparatus shown in FIG. 6.

10A to 15C are manufacturing process diagrams of the apparatus shown in FIGS. 6 to 9.

Explanation of symbols for the main parts of the drawings

100: active matrix 105: drain pad

110: protective layer 115: etch stop layer

117: air gap 120: first membrane

121: second membrane 125: first lower electrode

126: second lower electrode 130: first strained layer

131: second strained layer 135: first upper electrode

136: second upper electrode 137: first mirror post

138: second mirror post 145: mirror

150: beer hall 155: beer contact

160: metal wire 165: common electrode wire

170: first sacrificial layer 175: second sacrificial layer

180: first actuating part 190: second actuating part

In order to achieve the above object, the present invention provides an active matrix having an M × N (M, N is an integer) transistor and a drain pad formed on one side thereof, a first actuator formed on one side of the active matrix, Provided is a thin film type optical path control device including a second actuator formed on the other side of the active matrix, and a mirror formed on the first actuator and the second actuator.

The first actuating part includes a first membrane formed on one side of the active matrix, a first lower electrode formed on the first membrane, a first strained layer formed on the first lower electrode, and the first modified part. And a first upper electrode formed on top of the layer. The second actuating part includes a second membrane formed on the other side of the active matrix, a second lower electrode formed on the second membrane, a second deformation layer formed on the second lower electrode, and the second deformation. And a second upper electrode formed on top of the layer.

In the above-described thin film type optical path control device according to the present invention, a bias voltage is applied to upper electrodes of the plurality of actuating parts through pads of TCP, pads of AMA panels, and common electrode lines, respectively. At the same time, the image signals transmitted through the pads of the TCP and the pads of the AMA panel are applied to the lower electrodes of the plurality of actuators through transistors, drain pads, via contacts, and metal wires embedded in the active matrix. Accordingly, an electric field is generated between the plurality of upper electrodes and the lower electrode, and the plurality of deformation layers respectively cause deformation by the electric field. The strained layers contract in a direction perpendicular to the electric field, so that the plurality of actuators including the strained layers are bent in the same direction at a predetermined angle. The mirror reflecting the light beam incident from the light source is bent at the same angle as the actuating parts because it is supported by the plurality of mirror posts and formed on the actuating parts. Accordingly, the mirror reflects the incident light beam at a predetermined angle, and the reflected light beam passes through the slit and is projected onto the screen to form an image.

Therefore, the apparatus according to the present invention forms the actuators by avoiding the portion where the drain pad is formed on the active matrix, and then applies an image signal from the drain pad to the lower electrodes through the metal line, thereby providing the active matrix with the active matrix. Damage to the built-in transistor can be minimized. In addition, by forming a common electrode line thickly on one side of the actuating portions, it is possible to minimize the voltage drop inside the common electrode line to apply sufficient voltage to the upper electrodes to cause deformation of the strain layers. In addition, by applying the second sacrificial layer and supporting the mirror through the plurality of support parts, the horizontality of the mirror may be improved.

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

6 is a plan view of a thin film type optical path control apparatus according to an embodiment of the present invention, Figure 7 is a perspective view of the device shown in Figure 6, Figure 8 is a device shown in Figure 6 BB ' 9 is a cross-sectional view taken along the line, and FIG. 9 is a cross-sectional view taken along line CC ′ of the apparatus shown in FIG. 6, and FIGS. 10A to 15C are manufacturing process diagrams of the apparatus shown in FIGS. 6 to 9.

6 and 8, the thin film type optical path control apparatus includes an active matrix 100, a first actuating unit 180, and a second actuating unit 190. The active matrix 21 is a semiconductor wafer in which a metal oxide semiconductor (MOS) transistor (not shown), preferably a P-MOS transistor, is formed and is similar to an active matrix used on an LCD panel. That is, the active matrix 21 contains M × N transistors (M and N are integers) (not shown). In addition, a drain pad 105 electrically connected to each transistor is formed on a surface of the active matrix 21.

The first actuating part 180 may include a first membrane 120, a first bottom electrode 120, a first active layer 125, and a first top electrode. electrode 135, and a first mirror post 137. One side of the first membrane 120 is in contact with the upper portion of the active matrix 100 and the other side is bent at a right angle to form a parallel to the active matrix 100 via the air gap 117. That is, the first membrane 120 is formed in the shape of a mirror '′' on the active matrix 100. The first lower electrode 125 is stacked in the shape of a rectangle on the head portion of the mirror-shaped '′' of the first membrane 120. The first strained layer 130 is stacked on the first lower electrode 125 in a rectangular shape having a size smaller than that of the first lower electrode 125, and the first upper electrode 135 is formed of the first strained layer ( The upper portion of the 130 is stacked in a rectangular shape having a smaller size than the first deformable layer 130. A first mirror post 137 is formed on one side of the first upper electrode 135 to support the mirror 145 thereon.

6 and 9, the second actuator 190 may include a second membrane 121, a second lower electrode 126, a second strained layer 131, a second upper electrode 136, and A second mirror post 138. One side of the second membrane 121 is in contact with the active matrix 100, and the other side of the second membrane 121 is bent at a right angle to have a shape of 'b' parallel to the active matrix 100 via the air gap 117. Thus, the first membrane 120 and the second membrane 121 together have the shape of the letter 'C' on the same plane. The second lower electrode 126 is stacked in a rectangular shape on the leg portion of the 'b' of the second membrane 121, and the second deformable layer 131 is formed on the second lower electrode 126. The electrode 126 is stacked in a rectangular shape having a smaller size. The second upper electrode 136 is stacked on the second strained layer 131 in the shape of a rectangle having a smaller size than the second strained layer 131, and a second mirror is formed on one side of the second upper electrode 136. A post 138 is formed to support the mirror 145 formed thereon together with the first mirror post 137.

Under the portion where the first membrane 120 and the second membrane 121 are connected, the etch stop layer 115 and the protective layer 110 from the first membrane 120 and the second membrane 121. A via hole 150 is formed vertically, and a via contact 155 is formed in the via hole 150. In addition, an upper portion of the portion where the first membrane 120 and the second membrane 121 are connected, that is, a '-' shaped leg portion and the second membrane 121 on the mirror of the first membrane 120. A metal line 160 is formed at each head of the 'B' to electrically connect the via contact 155, the first lower electrode 125, and the second lower electrode 126. Therefore, the image signal is transferred from the transistor embedded in the active matrix 100 to the first lower electrode 125 and the second lower electrode 126 through the drain pad 105, the via contact 155, and the metal line 160. Is approved.

Applying a bias voltage to the first upper electrode 135 and the second upper electrode 136 on a portion adjacent to the portion where the first membrane 120 and the second membrane 121 are connected on the active matrix 100. The common electrode line 165 is formed to be parallel to the portion where the first membrane 120 and the second membrane 121 are connected. The common electrode line 165 is connected to the first upper electrode 135 and the second upper electrode 136. The mirror 145 is formed on the first actuator 180 and the second actuator 190 with the first mirror post 137 and the second mirror post 138 as a support.

Hereinafter, a method of manufacturing the above-described thin film type optical path control apparatus will be described in detail with reference to the accompanying drawings. 10A and 10B show a state in which the membrane 119 is formed in the apparatus shown in FIGS. 8 and 9.

Referring to FIGS. 10A and 10B, first, an MOS transistor, such as a P-type MOS transistor, which has a feature of increasing the degree of integration and is widely used in a large-scale integrated circuit as a semiconductor memory device, has M × N (M, N Integer matrix) is provided. Preferably, the active matrix 100 is made of a semiconductor such as silicon (Si). A drain pad 105 is formed on one surface of the active matrix 100. Next, a passivation layer 110 is formed on the active matrix 100 and the drain pad 105 by using a chemical vapor deposition (CVD) method of about 1.0 to 1.0 μm. It is formed to have a thickness of. The protective layer 110 is made of in-silicate glass (PSG) and prevents the active matrix 100 from being damaged during the subsequent process.

An etch stop layer 115 is stacked on the passivation layer 110. The etch stop layer 115 is deposited to a thickness of about 1000 to 2000 microns using nitride. The etch stop layer 115 is deposited using a low pressure chemical vapor deposition (LPCVD) process in which a thin film is deposited. That is, the etch stop layer 115 is formed by depositing nitride on the protective layer 110 using a chemical reaction of thermal energy in a low pressure (200 to 700 mm torr) reaction vessel. The etch stop layer 115 serves to prevent the active matrix 100 and the protective layer 110 from being etched and damaged during the subsequent etching process.

Subsequently, a first sacrificial layer 170 is deposited on the etch stop layer 115. The first sacrificial layer 170 functions to facilitate lamination to form the AMA module, and is removed by hydrogen fluoride (HF) vapor after the lamination of the AMA module is completed. The first sacrificial layer 170 is phosphorus silicate glass (PSG) having a high concentration of phosphorus (PG) using an atmospheric pressure chemical vapor deposition (Atmospheric Pressure Chemical Vapor Deposition: APCVD) process of about 0.5 to 2.0㎛ It is formed to a thickness of. That is, the first sacrificial layer 170 is deposited using a chemical reaction by thermal energy in a reaction vessel under atmospheric pressure (760 mm torr). On the other hand, since the first sacrificial layer 170 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 first sacrificial layer 170 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. Preferably, the surface of the first sacrificial layer 170 is planarized using a CMP process. Subsequently, the first sacrificial layer 170 is patterned to form positions of supporting portions of the first actuator 180 and the second actuator 190. That is, for example, the first sacrificial layer 170 is etched using an etching solution such as hydrogen fluoride (HF), or the first sacrificial layer 170 using plasma or an ion beam. ) To create a position where the support of the actuator is to be formed.

As described above, after the support portion formation position of the first actuating portion 180 and the second actuating portion 190 is made, the membrane 119 made of nitride is made into 0.01 to 1.0 mu m, preferably, It is formed to a thickness of about 0.4 μm. The membrane 119 is deposited using a low pressure chemical vapor deposition (LPCVD) process. At this time, the stress in the membrane 119 is controlled by forming the membrane 119 while changing the ratio of the reactive gas with time in the low pressure reaction vessel. The membrane 119 is later patterned into a first membrane 120 and a second membrane 121.

11A and 11B show a state in which the upper electrode 134 is formed in the apparatus shown in FIGS. 8 and 9.

Referring to FIGS. 11A and 11B, platinum (Pt) or platinum (Pt) -tantalum (Ta) is formed in a thickness of about 0.01 to 1.0 μm using a sputtering process on the membrane 119. The lower electrode 124, which is a signal electrode, is formed by evaporation. The lower electrode 124 is later patterned into the first lower electrode 125 and the second lower electrode 126. Subsequently, the strained layer 129 is formed by laminating piezoelectric ceramics or electrostrictive ceramics using a sol-gel method, a sputtering method, or a chemical vapor deposition (CVD) method. 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 PMN (Pb ( Mg, Nb) O ₃ ) is deposited. Preferably, PZT (Pb (Zr, Ti) O ₃ ) is laminated to a thickness of about 0.01 to 1.0 탆 to form a strained layer 129. Next, the strained layer 129 is subjected to a heat treatment using a rapid heat treatment (RTA) process to phase change. The strained layer 129 is later patterned into a first strained layer 130 and a second strained layer 131. Subsequently, aluminum (Al) or platinum (Pt) is sputtered on the strained layer 129 to form an upper electrode 134, which is a common electrode having a thickness of about 0.1 to 1.0 mu m.

12A and 12B show a state in which the membrane 119 is patterned in the apparatus shown in FIGS. 8 and 9.

12A and 12B, the upper electrode 134, the strained layer 129, the lower electrode 124, and the membrane 119 are sequentially patterned into a predetermined pixel shape. That is, after forming a photo resist layer (not shown) resistant to the material to be etched on the upper electrode 134, the upper electrode 134 is patterned to form the first upper electrode 135 and the first electrode. Two upper electrodes 136 are formed. The first upper electrode 135 and the second upper electrode 136 have a rectangular shape parallel to each other. Subsequently, after applying a photoresist layer (not shown) on the first upper electrode 135, the second upper electrode 136, and the strained layer 129, the strained layer 129 is patterned to form a first layer. The strained layer 130 and the second strained layer 131 are formed. In this manner, the lower electrode 124 is patterned to form the first lower electrode 125 and the second lower electrode 126.

Each of the first strained layer 130 and the second strained layer 131 has a rectangular shape parallel to each other that is slightly wider than the first upper electrode 135 and the second upper electrode 136, and the first lower electrode 125. The second lower electrode 126 also has a rectangular shape parallel to each other slightly wider than the first strained layer 130 and the second strained layer 131.

The membrane 119 is patterned into the first membrane 120 and the second membrane 121 in the same manner as above. Unlike the shape of the first lower electrode 125, the first membrane 120 has a mirror-shaped 'A' shape, and the first lower electrode 125 is formed on an upper portion of the head of the 'A' mirror image. do. Unlike the shape of the second lower electrode 126, the second membrane 121 is patterned in the shape of a 'b' so that the second lower electrode 126 is formed on the leg portion of the 'b'. The first membrane 120 and the second membrane 121 are connected to each other and have the shape of the letter 'c' together on the same plane.

13A to 13C show a state showing electrical wiring among the devices shown in FIGS. 8 and 9.

13A to 13C, a via hole 150 is formed by etching a portion in which a drain pad 105 is formed below a portion where the first membrane 120 and the second membrane 121 are connected. That is, the via holes 150 are vertically etched to the drain pad 105 by sequentially etching the etch stop layer 115 and the protective layer 110 from the portions where the first membrane 120 and the second membrane 121 are connected. Form. Subsequently, the via contact 155 may be formed by sputtering a metal such as platinum or platinum-tantalum on the inside of the via hole 150 and the portion where the first membrane 120 and the second membrane 121 are connected. And metal lines 160 are formed at the same time. In this case, the metal wire 160 has a thickness of about 0.1 to 1.0 μm and is connected to the first lower electrode 125 and the second lower electrode 126. As a result, the drain pad 105, the via contact 155, the metal wire 160, the first lower electrode 125, and the second lower electrode 126 are electrically connected to each other. Therefore, the image signal is transferred from the transistor embedded in the active matrix 100 to the first lower electrode 125 and the second lower electrode 126 through the drain pad 105, the via contact 155, and the metal line 160. Is approved. In the invention described in the preceding application, since the support, the lower electrode, the strain layer, and the upper electrode of the membrane are formed on the upper portion of the drained portion below, the transistor embedded in the active matrix is directly affected by the subsequent processes and damaged. There was a problem wearing. However, in the present invention, the first actuating part 180 and the second actuating part 190 are formed to avoid the portion where the drain pad 105 is formed on the active matrix 100, and drained through the metal wire 160. Since an image signal is applied from the pad 105 to the first lower electrode 125 and the second lower electrode 126, damage to the transistor built in the active matrix 100 can be minimized.

The metal line 160 and the via contact 155 are formed, and at the same time, the common electrode line 165 is formed on one side of the portion where the first membrane 120 and the second membrane 121 are connected. The common electrode line 165 is formed of a metal such as platinum, platinum-tantalum, aluminum, or silver so as to have a thickness of about 0.5 to about 2.0 μm by the sputtering method, and then the first upper electrode 135 and It is patterned into a predetermined shape so as to be connected to the second upper electrode 136. In the related art, since the common electrode line is thinly formed on the rear surface of the pixel in order to apply a voltage to the upper electrode, a voltage drop occurs due to a resistance inside the common electrode line, so that it is difficult to apply sufficient voltage to the upper electrode to drive the strained layer. In contrast, the present invention forms the common electrode line 165 thickly on one side of the first actuating part 180 and the second actuating part 190 as described above, thereby providing the first upper electrode 135 and the second upper part. Sufficient voltage necessary for the first strained layer 130 and the second strained layer 131 to cause deformation may be applied to the electrode 136.

14A to 14C show a state in which the mirror 145 is formed among the devices shown in FIGS. 8 and 9.

14A to 14C, after the patterning is completed as described above, the first sacrificial layer 170 is removed using hydrogen fluoride (HF) vapor to form an air gap 117. Subsequently, the second sacrificial layer 175 is formed by applying a polymer having excellent fluidity to the entire surface of the result using a spin coating method. The second sacrificial layer 175 is formed to a predetermined height above the first upper electrode 135 and the second upper electrode 136 while completely filling the air gap 117. Subsequently, the second sacrificial layer 175 is patterned to expose one side of the first upper electrode 135 and the second upper electrode 136, respectively. After sputtering a metal such as silver, aluminum, or platinum on one side of the exposed first upper electrode 135 and the second upper electrode 136 and the upper portion of the second sacrificial layer 175, the patterned mirror ( 145 and the first mirror post 137 and the second mirror post 138 are formed simultaneously. Accordingly, the mirror 145 is supported by the first mirror post 137 on the first upper electrode 135 and the second mirror post 138 on the second upper electrode 136, and the first actuator It is formed in the shape of a rectangle to cover the casting portion 180, the second actuating portion 190, and some of the adjacent actuating portions. As described above, in the present invention, by supporting the mirror 145 through two support portions, the horizontal degree of the mirror 145 can be improved.

15A to 15C show a state in which the apparatus shown in FIGS. 8 and 9 is completed.

15A to 15C, after the second sacrificial layer 175 is removed using an oxygen (O ₂ ) plasma, the resultant is cleaned and dried to form a mirror 145 thereon. The manufacturing of the actuating part 180 and the second actuating part 190 is completed. Subsequently, a metal such as chromium (Cr), nickel (Ni), or gold (Au) is deposited on the bottom of the active matrix 100 using a sputtering method or an evaporation method to resist contact (ohmic contact). (Not shown). In addition, a bias voltage is applied to the first upper electrode 135 and the second upper electrode 136, which are subsequent common electrodes, through the common electrode line 165, and the first lower electrode 125 and the second lower electrode, which are signal electrodes, are applied. The active matrix 100 is cut in preparation for TCP (Tape Carrier Package) bonding for applying an image signal to the electrode 126. In this case, the active matrix 100 is cut only to a predetermined thickness in preparation for the subsequent process. Subsequently, the pad (not shown) of the AMA panel and the pad (not shown) of the TCP are connected to complete manufacturing of the thin film AMA module.

In the above-described thin film type optical path control apparatus according to an embodiment of the present invention, the first upper electrode 135 and the second upper electrode 136 are biased through a pad of TCP, a pad of an AMA panel, and a common electrode line 165. Voltage is applied. At the same time, the image signal transmitted through the pad of the TCP and the pad of the AMA panel is transferred to the first lower electrode through the transistor, the drain pad 105, the via contact 155, and the metal wire 160 embedded in the active matrix 100. And the second lower electrode 126. Accordingly, an electric field is generated between the first upper electrode 135 and the first lower electrode 125 and the second upper electrode 136 and the second lower electrode 126, respectively. Each of the first strained layer 130 between the first lower electrode 125 and the second strained layer 131 between the second upper electrode 136 and the second lower electrode 126 causes deformation.

The first strained layer 130 and the second strained layer 131 contract in a direction perpendicular to the electric field, and thus, the first actuating part 180 and the second strain including the first strained layer 130. The second actuating part 190 including the layer 131 is bent in the same direction at an angle. The mirror 145 reflecting the light beam incident from the light source is supported by the first mirror post 137 and the second mirror post 138 so that the first actuator 180 and the second actuator 190 Since it is formed in the upper portion is bent at the same angle as the first actuator 180 and the second actuator 190. Accordingly, the mirror 145 reflects the incident light beam at a predetermined angle, and the reflected light beam passes through the slit and is projected onto the screen to form an image.

As described above, in the thin film type optical path adjusting device according to the present invention, after forming the first actuator portion and the second actuator portion avoiding the portion where the drain pad is formed on the active matrix, the first actuator portion is formed from the drain pad through the metal wire. Since an image signal is applied to the lower electrode and the second lower electrode, damage to the transistor embedded in the active matrix can be minimized.

In addition, by forming a common electrode line thickly on one side of the first actuating part and the second actuating part, the voltage drop inside the common electrode line is minimized, so that the first strained layer and the second strain on the first upper electrode and the second upper electrode. Sufficient voltage may be applied to the layer to cause deformation. Then, by applying the second sacrificial layer and supporting the mirror through the two supporting portions, the horizontality of the mirror can be improved.

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

Claims (12)

An active matrix 100 having M × N (M, N is an integer) transistors and a drain pad 105 formed on one side thereof; Iii) a first membrane 120 formed on one side of the active matrix 100, ii) a first lower electrode 125 formed on the first membrane 120, iii) a first lower electrode 125 A first actuating part (180) including a first strained layer (130) formed on the upper part) and a first upper electrode (135) formed on the first strained layer (130); a) a second membrane 121 formed on the other side of the active matrix 100, b) a second lower electrode 126 formed on the second membrane 121, c) the second lower electrode 126. A second actuating part 190 including a second deformed layer 131 formed on the upper surface of the upper surface of the second deformed layer 131 and a second upper electrode 136 formed on the second deformed layer 131; And Thin film type optical path control device comprising a mirror (145) formed on the first actuating portion (180) and the second actuating portion (190). The protective layer 110 of claim 1, wherein the active matrix 100 is formed on the active matrix 100 and the drain pad 105 to protect the active matrix 100. The thin film type optical path control device, characterized in that it further comprises an etch stop layer (115) formed on the (110) to prevent the protective layer (110) and the active matrix (100) is etched. The apparatus of claim 1, wherein the first actuating part (180) and the second actuating part (190) are driven in the same direction. The method of claim 1, wherein the first membrane 120 is formed in the shape of a mirror-shaped 'a' on top of the active matrix 100, the first lower electrode 125 is formed of the 'a' shaped of the mirror It is formed in a rectangular shape on the top of the head portion, the first deformable layer 130 is formed in a rectangular shape of a smaller size than the first lower electrode 125 on the first lower electrode 125, And the first upper electrode 135 is formed in the shape of a rectangle having a smaller size than the first strained layer 130 on the first strained layer 130. The method of claim 4, wherein the second membrane 121 is formed in the shape of the 'b' on the top of the active matrix 100, the second lower electrode 126 is the upper portion of the leg portion of the 'b' The second deformable layer 131 is formed in a rectangular shape having a smaller size than the second lower electrode 126 on the second lower electrode 126, and the second deformable layer 131 is formed on the second lower electrode 126. The upper electrode 136 is a thin film type optical path control device, characterized in that formed on the top of the second strained layer (131) in the shape of a rectangle smaller than the second strained layer (131). The apparatus of claim 5, wherein the first membrane (120) and the second membrane (121) are connected to each other and have a shape of a letter 'c' on the same plane. 7. The drain pad 105 of claim 6, wherein a portion of the first membrane 120 and the second membrane 121 is connected to each other under the first membrane 120 and the second membrane 121. The via hole 150 is formed vertically to the via hole, a via contact 155 is formed in the via hole 150, and a portion in which the first membrane 120 and the second membrane 121 are connected to each other. A metal line 160 is formed on the upper portion of the drain pad 105 to connect the first lower electrode 125 and the second lower electrode 126 through the via contact 155 and the metal line 160. Thin film type optical path control device, characterized in that. The thin film type optical path control device according to claim 7, wherein the metal wire (160) has a thickness of 0.1 to 1.0 탆 using platinum (Pt) or platinum-tantalum (Pt-Ta). The method of claim 1, wherein the first actuator 180 further includes a first mirror post 137 formed on one side of the first upper electrode 135, the second actuator 190 The thin film type optical path control device further comprises a second mirror post (138) formed on one side of the second upper electrode (136). The apparatus of claim 9, wherein the mirror 145 is supported by the first mirror post 137 and the second mirror post 138, and has a rectangular flat plate shape. . The thin film type optical path control apparatus of claim 1, further comprising a common electrode line 165 formed on one side of the first actuating part 180 and the second actuating part 190. Light path control device. The thin film type optical path of claim 11, wherein the common electrode line 165 has a thickness of 0.5 to 2.0 μm using any one selected from the group consisting of platinum, platinum-tantalum, aluminum, and silver. Regulating device.

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