KR20000003886A - Method for manufacturing a thin film actuated mirror array - Google Patents

Abstract

PURPOSE: A method for manufacturing a thin film actuated mirrors array in an optical projection system is provided to increase a degree of horizontal of the mirror formed on the top of a second sacrificial layer. CONSTITUTION: The method for manufacturing a thin film actuated mirrors array comprising the step of: providing an active matrix (100) including a first metal layer (135), which a MOS transistor is built-in and a drain pad extending from a drain of the transistor; forming and patterning a first sacrificial layer (160) onto the active matrix by using an amorphous silicon, and then forming a support layer (170) on the first sacrificial layer; forming a first actuating layer (210) including a first lower electrode (180), a first deformable layer (190), and a upper electrode (200) and a second actuating layer (211) including a second electrode (181), a second deformable layer (191), and a upper electrode layer (201) onto the support layer; forming a amorphous silicon layer onto the support layer, the first actuating layer and the second actuating layer and then a second sacrificial layer (300) including the step of the forming the amorphous silicon; forming a mirror (260) on the second sacrificial; and removing the first and second sacrificial layers.

Description

Manufacturing method of thin film type optical path control device

The present invention relates to a thin film type optical path control apparatus using AMA (Actuated Mirror Array) and a method of manufacturing the same. More particularly, the second sacrificial layer is easily formed and the flatness of the second sacrificial layer is improved. The present invention relates to a method for manufacturing a thin film type optical path control device capable of improving the horizontality of a formed mirror.

Optical path control devices or spatial light modulators for projecting optical energy onto a screen may be applied to various fields such as optical communication, image processing, and information display devices. Typically, image processing apparatuses using such an optical modulator are classified into a direct-view image display device and a projection-type image display device according to a method of displaying optical energy on a screen. do.

An example of a direct-view image display device is a CRT (Cathode Ray Tube). The CRT device is called a CRT, which has excellent image quality but increases in weight and volume as the screen is enlarged, leading to an increase in manufacturing cost. There is. Projection-type image display devices include a liquid crystal display (LCD), a deformable mirror device (DMD), and an AMA. Such projection image display devices can be further divided into two groups according to their optical characteristics. That is, devices such as LCDs can be classified as transmissive spatial light modulators, while DMD and AMA can be classified as reflective spatial light modulators.

Transmission optical modulators, such as LCDs, have a very simple optical structure, which makes them thinner, lighter in weight, and smaller in volume. However, due to the polarity of the light, the light efficiency is low, there is a problem inherent in the liquid crystal material, for example, there is a disadvantage that the response speed is slow and the inside is easy to overheat. In addition, the maximum light efficiency of existing transmission light modulators is limited to a range of 1-2%, requiring dark room conditions to provide acceptable display quality. Therefore, optical modulators such as DMD and AMA have been developed to solve the above problems.

Although DMD shows a relatively good light efficiency of about 5%, the hinge structure employed in the DMD not only causes serious fatigue problems, but also requires a very complicated and expensive driving circuit. In the AMA, each of the mirrors installed therein reflects light incident from the light source at a predetermined angle, and the reflected light is projected on the screen through an aperture such as a slit or a pinhole. It is a device that can adjust the speed of light to form an image. Therefore, its structure and operation principle are simple, and high light efficiency (more than 10% light efficiency) can be obtained compared to LCD or DMD. In addition, the contrast of the image projected on the screen is improved to obtain a brighter and clearer image.

Each actuator of the AMA generates a deformation in accordance with the electric field generated by the applied electric picture signal and the bias signal. As the actuator deforms, each of the mirrors mounted thereon is tilted. Accordingly, the inclined mirrors reflect light incident from the light source at a predetermined angle to form an image on the screen. Piezoelectric materials such as PZT (Pb (Zr, Ti) O ₃ ) or PLZT ((Pb, La) (Zr, Ti) O ₃ ) are used as actuators for driving the respective mirrors. The actuator may also be configured as a warping material such as PMN (Pb (Mg, Nb) O ₃ ).

These AMA devices are largely divided into bulk type and thin film type. The bulk optical path control device is disclosed in US Pat. No. 5,085,497 to Gregory Um et al. The bulk optical path 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 using a sawing method and mirrors the upper portion thereof. By installing. However, the bulk optical path control device requires very high precision in design and manufacturing, and has a disadvantage in that the response of the strained layer is slow.

Accordingly, a thin film type optical path control apparatus that can be manufactured using a semiconductor manufacturing process has been developed. The thin film type optical path control device is disclosed in Korean Patent Application No. 98-????? (name of the invention: thin film type optical path control device and a method of manufacturing the same) filed by the present applicant with the Korean Patent Office on January 1, 199.

1 is a cross-sectional view of the thin film type optical path control device. Referring to FIG. 1, the thin film type optical path adjusting device includes an active matrix 1, a support element 50 formed on the active matrix 1, and a first actuator formed side by side on the support element 50. 70) and a second actuator 71, and a mirror 60 formed on the first actuator 70 and the second actuator 71.

The active matrix 1 in which M x N (M and N are natural numbers) containing P-MOS transistors 5 extends from the drain 3 and the source 4 of the P-MOS transistor 5 to be active. The first metal layer 10 stacked on the matrix 1, the first protective layer 15 stacked on the first metal layer 10, and the second metal layer stacked on the first protective layer 15. 20, a second protective layer 25 stacked on the second metal layer 20, and an etch stop layer 30 stacked on the second protective layer 25.

The support element 50 comprises a support line 48, a support layer 40, a first anchor 45 and second anchors 46a, 46b. The support line 48 and the support layer 40 are formed horizontally on top of the active matrix 1 via the first air gap 37. The support layer 40 has a rectangular ring shape and is integrally formed with the support line 48 on one side of the support line 48 along a direction orthogonal to the support line 48 in the same plane. A first anchor 45 is integrally formed with the two arms and attached to the etch stop layer 30 at a lower portion between the two arms horizontally extending in a direction orthogonal to the support line 48 of the support layer 40. Two second anchors 46a and 46b are formed integrally with the two arms, respectively, and are attached to the etch stop layer 30 at the outer lower portion of the four arms.

The first anchor 45 is formed on a portion in which the drain pad of the first metal layer 10 is formed below the etch stop layer 30. The first metal layer 10 is formed at the central portion of the first anchor 45 through the etch stop layer 30, the second passivation layer 25, the opening 21 of the second metal layer 20, and the first passivation layer 15. The via hole 95 is formed to the drain pad of the via hole, and the via contact 96 is formed inside the via hole 95.

The first actuating part 70 and the second actuating part 71 are each formed side by side in the shape of a rectangle on top of the two arms of the support layer 40. The first actuating part 70 includes a first lower electrode 55, a first deformable layer 60, and a first upper electrode 65, and the second actuating part 71 includes a second lower electrode ( 56, a second strained layer 61, and a second upper electrode 66.

A portion of the support layer 40 having the annular shape of the quadrangle is not formed in the first actuating part 70 and the second actuating part 71, that is, a part formed in parallel with the support line 48. A post 85 supporting 90 is formed. The mirror 90 is centrally supported by the post 85 and both sides thereof are formed horizontally on the upper portion of the first actuating part 70 and the second actuating part 71 via the second air gap 38. do.

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

2A to 2D are manufacturing process diagrams of the apparatus shown in FIG. 1. Referring to FIG. 2A, after the insulating film 2 made of oxide is formed on the resultant P-MOS transistor 5 is formed, the upper part of one side of the source 4 and the drain 3 is formed by using a photolithography method. Form openings that expose. After depositing the first metal layer 10 made of titanium, titanium nitride, tungsten, nitride, or the like on the resultant, the first metal layer 10 is patterned by photolithography. The first passivation layer 15 is stacked on the first metal layer 10 and the active matrix 1. The first protective layer 15 is formed to have a thickness of about 8000 GPa by using the silicate glass (PSG) method by chemical vapor deposition (CVD). The first protective layer 15 prevents damage to the active matrix 1 in which the P-MOS transistor 5 is embedded during the subsequent process.

The second metal layer 20 is stacked on the first protective layer 25. The second metal layer 20 forms a titanium layer having a thickness of about 300 kW using a sputtering method of titanium, and then a thickness of about 1200 kW using a physical vapor deposition method (PVD) of titanium nitride on the titanium layer. To form a titanium nitride layer having a.

The second passivation layer 25 is stacked on the second metal layer 20. The second protective layer 25 is formed to have a thickness of about 2000 kPa by using the chemical vapor deposition method. An etch stop layer 30 is stacked on the second passivation layer 25. The etch stop layer 30 is formed by depositing nitride by low pressure chemical vapor deposition (LPCVD).

The first sacrificial layer 35 is stacked on the etch stop layer 30. The first sacrificial layer 35 is formed to have a thickness of about 2.0 to 3.0 μm by using a low pressure chemical vapor deposition method at a temperature of about 500 ° C. or less. Next, the surface of the first sacrificial layer 35 is polished using a chemical mechanical polishing method to planarize the surface.

Referring to FIG. 2B, a first layer 39 is stacked on the exposed etch stop layer 30 and on the first sacrificial layer 35. The first layer 39 is formed to have a thickness of about 0.1 to 1.0 μm using a low pressure chemical vapor deposition method to form a hard material such as nitride. The first layer 39 is later patterned with a support element 50. The lower electrode layer 54 is stacked on top of the first layer 39. The lower electrode layer 54 is formed to have a thickness of about 0.1 to 1.0 µm using a metal such as platinum, tantalum or platinum-tantalum by sputtering or chemical vapor deposition.

On the upper portion of the lower electrode layer 54, a piezoelectric material, such as PZT or PLZT, is formed by using a sol-gel method, a sputtering method, or a chemical vapor deposition (CVD) method. It is formed to have a thickness of. Subsequently, the piezoelectric material constituting the second layer 59 is phase shifted by using a rapid heat treatment (RTA) method. The second layer 59 is the first strained layer 60 and the second upper electrode 66 which are later deformed by a first electric field generated between the first upper electrode 65 and the first lower electrode 55. And a second strained layer 61 causing deformation by a second electric field generated between the second lower electrode 56 and the second lower electrode 56.

The upper electrode layer 64 is stacked on top of the second layer 59. The upper electrode layer 64 is formed to have a thickness of about 0.1 to 1.0 µm using a metal having electrical conductivity such as platinum, tantalum, silver or platinum-tantalum using a sputtering method or a chemical vapor deposition method. The upper electrode layer 64 is later patterned with a first upper electrode 65 and a second upper electrode 66 each having a second signal (bias signal) applied and spaced apart by a predetermined distance.

Referring to FIG. 2C, after applying and patterning a second photoresist (not shown) on top of the upper electrode layer 64, the upper electrode layer 64 is formed of a rectangular flat plate using the second photoresist as a mask. The first upper electrode 65 and the second upper electrode 66 having a shape and separated from each other by a predetermined distance are patterned. The second signal is applied to the first upper electrode 65 and the second upper electrode 66 through a common electrode line 67 formed later from the outside, respectively. Subsequently, the second photoresist is removed.

Subsequently, the second layer 59 is patterned in the same manner as the method of patterning the upper electrode layer 64 into the first upper electrode 65 and the second upper electrode 66 to have a rectangular flat plate shape. The first strained layer 60 and the second strained layer 61 are formed to be separated from each other by a predetermined distance and formed side by side. Subsequently, the lower electrode layer 54 is patterned in the same manner as the patterning of the upper electrode layer 64 to form a rectangular flat plate, and the first lower electrode 55 and the second lower electrode spaced apart from each other by a predetermined distance. Form 56. In addition, when the lower electrode layer 54 is patterned, the common electrode line 67 formed in a direction orthogonal to the first lower electrode 55 and the second lower electrode 56 on one side of the first layer 39. ) Is formed simultaneously with the first lower electrode 55 and the second lower electrode 56. Each of the first lower electrode 55 and the second lower electrode 56 has a slightly larger area than the first strained layer 60 and the second strained layer 61, and the common electrode line 67 is formed later. A portion of the 48 may be spaced apart from the first lower electrode 55 and the second lower electrode 56 by a predetermined distance. The first layer 39 is patterned to form a support element 50 comprising a support layer 40, a support line 48, a first anchor 45 and second anchors 46a, 46b. At this time, both sides of the first layer 39 in contact with the etch stop layer 30 exposed in the shape of the three squares, the second anchors (46a, 46b) has a shape of a rectangular box, respectively, The opening 21 of the second metal layer 20 is formed below the first anchor 45.

The support layer 40 has a rectangular annular shape and is integrally formed with the supporting line 48 on one side of the supporting line 48 along a direction orthogonal to the supporting line 48 in the same plane, and has a rectangular annular shape. A first anchor 45 is integrally formed with the two arms and attached to the etch stop layer 30 at a lower portion between the two arms horizontally extending in a direction orthogonal to the support line 48 of the support layer 40. In an outer lower portion of the two arms, two second anchors 46a and 46b are formed integrally with the two arms, respectively, and are attached to the etch stop layer 30. The first anchor 45 and the second anchors 46a and 46b together supporting the support layer 40 are formed in the lower portion of the support layer 40 adjacent to the support line 48. A third photoresist (not shown) on top of the support element 50 including the support layer 40 and the support line 48 and on top of the first and second actuating portions 70 and 71. Is applied and patterned to expose the first upper electrode 65 and the second upper electrode 66 from the common electrode line 67 formed on the support line 48. At this time, portions from the first anchor 45 to the first lower electrode 55 and the second lower electrode 56 are also exposed. The first strained layer 60 and the first lower electrode 55 are removed from a portion of the first upper electrode 65 by depositing and patterning amorphous silicon or silicon dioxide or phosphorus pentoxide, which is a low temperature oxide, on the exposed portion. The first insulating layer 75 is formed up to a part of the support layer 40, and at the same time, the support layer 40 is formed from the part of the second upper electrode 66 through the second strained layer 61 and the second lower electrode 56. The second insulating layer 76 is formed so as to have a thickness of about 0.2 to 0.4 m, preferably about 0.3 m, by a low pressure chemical vapor deposition method.

The first anchor 45, the etch stop layer 30, and the second protection from the center upper portion of the first anchor 45, which is a portion in which the opening of the second metal layer 20 and the drain pad of the first metal layer 10 are formed below. After etching the layer 25 and the first protective layer 25 to form a via hole 95 to the drain pad, a via contact 96 is formed in the via hole 95, and the via hole 95 is formed. The first lower electrode connecting member 82 and the second lower electrode connecting member 83 are formed from the first lower electrode 55 and the second lower electrode 56, respectively. At the same time, the first upper electrode connecting member 80 and the second upper electrode 66 extend from the first upper electrode 65 to the common electrode line 67 through a part of the first insulating layer 75 and the support layer 40. The second upper electrode connecting member 81 is formed to the common electrode line 67 through a portion of the second insulating layer 76 and the support layer 40. The via contact 96, the first lower electrode connecting member 82, the second lower electrode connecting member 83, the first upper electrode connecting member 80, and the second upper electrode connecting member 81 are platinum or platinum, respectively. Tantalum is deposited by a sputtering method or a chemical vapor deposition method to have a thickness of about 0.1 to 0.2 µm, and then patterned.

Referring to FIG. 2D, polycrystalline silicon is deposited on the first actuator 70, the second actuator 71, and the support element 50 using a low pressure chemical vapor deposition method. ) And a second sacrificial layer 36 having a sufficient height to completely cover the second actuating portion 71. Subsequently, the surface of the second sacrificial layer 36 is planarized by using a chemical mechanical polishing method so that the top of the second sacrificial layer 36 has a flat surface. Subsequently, by patterning the second sacrificial layer 36 to form the mirror 90 and the post 85, the portion of the support layer 40 having a square annular shape, which is formed without being adjacent to the support line 48, is formed in parallel. Expose a portion of the. Next, a part of the exposed support layer 40 and the upper part of the second sacrificial layer 36 are laminated with a metal such as aluminum having excellent reflectivity using a sputtering method or a chemical vapor deposition method and patterning the deposited metal. A mirror 90 and a post 85 having a shape of a square plate are formed.

Then, the first sacrificial layer 35 and the second sacrificial layer 36 are removed using xenon fluoride or bromide fluoride, and the active matrix 1 having the actuators 70 and 71 is cleaned and dried. This completes the AMA device as shown in FIG.

However, in the above-described method for manufacturing a thin film type optical path control device, the polycrystalline silicon constituting the second sacrificial layer adheres to a metal such as platinum, which is a material constituting the first and second upper electrodes and the first and second lower electrodes. A problem arises in that it is difficult to uniformly deposit the second sacrificial layer due to poor properties. Therefore, there is a problem in that the flatness of the second sacrificial layer is lowered and the level of the mirror falls when the mirror is formed thereon.

Accordingly, an object of the present invention is to provide a second sacrificial layer by easily forming a second sacrificial layer using amorphous silicon and polycrystalline silicon on the first actuating portion and the second actuating portion and improving its flatness. It is to provide a method of manufacturing a thin film type optical path control apparatus that can improve the horizontal level of the mirror formed on the upper portion of the.

1 is a cross-sectional view of a thin film type optical path control device according to the present invention of the present applicant.

2A to 2D are manufacturing process diagrams of the apparatus shown in FIG. 1.

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

4 is a perspective view of the apparatus shown in FIG. 3.

FIG. 5 is a cross-sectional view of the apparatus shown in FIG. _{3 taken along} line A ₁ A _2. FIG.

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

<Explanation of symbols for main parts of drawing>

100: active matrix 120: transistor

135: first metal layer 140: first protective layer

145: second metal layer 150: second protective layer

155: etch stop layer 160: first sacrificial layer

170: support layer 171: first anchor

172a, 172b: second anchor 174: support line

175: support elements 180, 181: first and second lower electrodes

190, 191: First and second strained layers 200, 201: First and second upper electrodes

210, 211: first and second actuating parts

220, 221: first and second insulating layers

230, 231: first and second upper electrode connection members

250: Post 260: Mirror

270: Beer Hall 280: Beer Contact

290 and 291: first and second lower electrode connection members

300: second sacrificial layer

In order to achieve the object of the present invention described above, the present invention provides an active matrix comprising a first metal layer having a drain pad in which a MOS transistor is embedded and extending from the drain of the transistor, wherein a polycrystalline silicon is placed on top of the active matrix. After forming and patterning a first sacrificial layer, a support element is formed on top of the first sacrificial layer, the first comprising a first lower electrode, a first strained layer and a first upper electrode on top of the support layer. After forming the actuating portion and the second actuating portion including the second lower electrode, the second deformable layer, and the second upper electrode, an amorphous part is formed on top of the support element, the first actuating portion and the second actuating portion. Forming a second sacrificial layer consisting of a silicon layer and a polycrystalline silicon layer, forming a mirror on top of the second sacrificial layer, and removing the first sacrificial layer and the second sacrificial layer It provides a method for producing the optical path control type device. The second sacrificial layer is formed by forming an amorphous silicon layer by a plasma enhanced chemical vapor deposition method, then forming a polycrystalline silicon layer by a low pressure chemical vapor deposition method and planarizing the surface thereof by a chemical mechanical polishing method.

According to the present invention, a second sacrificial layer is formed on the support element, on the first and second actuating portions, with a second silicon layer having an amorphous silicon layer having excellent adhesion to metal and a polycrystalline silicon layer deposited thereon. The sacrificial layer can be easily formed and the uniformity and flatness of the second sacrificial layer can be improved. Therefore, the horizontality of the mirror formed on the upper portion of the second sacrificial layer can be improved, and thus the image quality of the image projected onto the screen can be improved.

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

3 is a plan view showing a thin film type optical path control device according to the present invention, Figure 4 shows an enlarged perspective view of the actuator and the mirror of the device of Figure 3, Figure 5 shows the device of Figure 3 A ₁ A ₂ The cross-sectional view is shown in a line.

3 and 4, the thin film type optical path adjusting device according to the present invention includes an active matrix 100, a support element 175 formed on the active matrix 100, and a top of the support element 175. The first actuating part 210 and the second actuating part 211 and the mirror 260 formed on the first actuating part 210 and the second actuating part 211 are formed.

Referring to FIG. 5, the active matrix 100 having M × N (M, N being a natural number) P-MOS transistors 120 includes a drain 105 and a source of the P-MOS transistors 120. A first metal layer 135 formed on top of the active matrix 100, a first passivation layer 140 formed on the first metal layer 135, and a first passivation layer 140 formed on the active matrix 100. The second metal layer 145, the second passivation layer 150 formed on the second metal layer 145, and the etch stop layer 155 formed on the second passivation layer 150 are included. The first metal layer 135 includes a drain pad extending from the drain 105 of the P-MOS transistor 120 to the bottom of the first anchor 171 to transmit a first signal (image signal). The second metal layer 145 is formed of a titanium (Ti) layer and a titanium nitride (TiN) layer, and a hole (not shown) is formed in a portion of the second metal layer 145 in which the drain pad is formed. do.

4 and 5, the support element 175 includes a support line 174, a support layer 170, a first anchor 171, and second anchors 172a, 172b. The support line 174 and the support layer 170 are horizontally formed on the active matrix 100 through the first air gap 165. The common electrode line 240 is formed on the support line 174, and the support line 174 serves to support the common electrode line 240.

The support layer 170 has a rectangular annular shape, preferably a rectangular annular shape, and is integral with the support line 174 on one side of the support line 174 along a direction perpendicular to the support plane 174 in the same plane orthogonal to the support line 174. Is formed. A first anchor 171 is integrally formed with the two arms at a lower portion between two arms horizontally extending in a direction orthogonal to the support line 174 of the support layer 170 having a rectangular ring shape. It is attached to the etch stop layer 155, and two second anchors 172a and 172b are formed integrally with the two arms and attached to the etch stop layer 155 at the lower outer side of the two arms.

The first anchor 171 and the second anchors 172a and 172b respectively supporting the support layer 170 are formed at a lower portion of the support layer 170 adjacent to the support line 174 so that the etch stop layer 155 is formed. Is attached to. The first anchor 171 and the second anchors 172a and 172b each have a shape of a rectangular box. The support layer 170 is supported at the center by the first anchor 171 and is supported at both sides by the second anchors 172a and 172b, so that the cross section of the support layer 170 and the anchors 171, 172a and 172b is provided. Has the shape of a 'T' as shown in FIG.

The first anchor 171 is formed on a portion in which the drain pad of the first metal layer 135 is formed below the etch stop layer 155. The drain of the first metal layer 135 is formed in the center of the first anchor 171 through the etch stop layer 155, the second passivation layer 150, the hole of the second metal layer 145, and the first passivation layer 140. The via hole 270 is formed to the pad, and the via contact 280 is formed inside the via hole 270.

The first actuating part 210 and the second actuating part 211 are formed in parallel with each other in the shape of a rectangle on top of the two arms of the support layer 170, respectively. The first actuating part 210 includes a first lower electrode 180, a first deformable layer 190, and a first upper electrode 200, and the second actuating part 211 includes a second lower electrode ( 181, a second strained layer 191, and a second upper electrode 201.

The first lower electrode 180 is formed in the shape of a quadrangle having a protrusion formed on one side of one of the two arms of the support layer 170, preferably, a mirror-shaped 'L' shape to form the support line. 174 is spaced apart by a predetermined distance. The protrusion of the first lower electrode 180 is formed on the first anchor 171 and extends to a portion adjacent to the via hole 270.

The first strained layer 190 has a rectangular shape having a smaller area than the first lower electrode 180, and is formed on the first lower electrode 180, and the first upper electrode 200 is formed of the first strained layer ( The upper surface of the first deformable layer 190 may be formed in the shape of a quadrangle having a smaller area than that of the surface of the first deformation layer 190.

The second lower electrode 181 has a quadrangular shape having a protrusion formed on one side of the two arms of the support layer 170 on the other side thereof, preferably, has a 'L' shape and has a first lower electrode 181. Are parallel to each other and spaced apart from the support line 174 by a predetermined distance. The protrusion of the second lower electrode 181 is formed on the first anchor 171 and extends to a portion adjacent to the via hole 270. Thus, the protrusion of the first lower electrode 180 and the protrusion of the second lower electrode 181 are spaced apart from each other by a predetermined distance with respect to the via hole 270.

The second deformable layer 191 has a rectangular shape having a smaller area than the second lower electrode 181, and is formed on the second lower electrode 181, and the second upper electrode 201 is formed of the second deformed layer ( It is formed on top of the second deformable layer 191 in the shape of a rectangle having a smaller area than 191.

A first lower electrode connecting member 290 is formed from the via contact 280 formed at the center of the first anchor 171 to the protrusion of the first lower electrode 180, and the second lower contact is formed from the via contact 280. The second lower electrode connecting member 291 is formed to the protrusion of the electrode 181. Accordingly, the drain pad of the first metal layer 135 and the first lower electrode 180 are connected to each other through the via contact 280 and the first lower electrode connecting member 290, and the second lower electrode 181 is via. The contact 280 and the second lower electrode connecting member 291 are connected to the drain pad of the first metal layer 135.

The support layer 170 may be formed through the first strained layer 190 and the first lower electrode 180 from one side of the first upper electrode 200 of the first upper electrode 200 adjacent to the support line 174. The first insulating layer 220 is partially formed. The first upper electrode connecting member 230 is formed from one side of the first upper electrode 200 to the common electrode line 240 through a portion of the first insulating layer 220 and the support layer 170. The first upper electrode connecting member 230 connects the first upper electrode 200 and the common electrode line 240 to each other, and the first insulating layer 220 under the first upper electrode connecting member 230 is formed in the first upper portion. The electrode 200 and the first lower electrode 180 are connected to each other to prevent an electrical short.

In addition, the support layer 170 is formed through the second strained layer 191 and the second lower electrode 181 from one side of the second upper electrode 201 of the portion of the second upper electrode 201 adjacent to the support line 174. The second insulating layer 221 is formed up to a portion of the second, and the second insulating layer 221 is formed from one side of the second upper electrode 201 to the common electrode line 240 through a portion of the second insulating layer 221 and the support layer 170. The upper electrode connecting member 231 is formed. The second insulating layer 221 and the second upper electrode connecting member 231 are formed to be parallel to the first insulating layer 220 and the first upper electrode connecting member 230, respectively. The second upper electrode connecting member 231 connects the second upper electrode 201 and the common electrode line 240 to each other, and the second insulating layer 221 below the second upper electrode connecting member 231 is connected to the second upper electrode. The electrode 201 and the second lower electrode 181 are connected to each other to prevent an electrical short circuit.

A portion of the support layer 170 having a rectangular annular shape, in which the first actuating part 210 and the second actuating part 211 are not formed, that is, a part formed parallel to the support line 174, is formed in a mirror ( A post 250 supporting 260 is formed. The mirror 260 is supported at the center by the post 250, and both sides thereof are parallel to the upper portion of the first actuator 210 and the second actuator 211 through the second air gap 310. Is formed. The mirror 260 serves to reflect light incident from a light source (not shown) at a predetermined angle.

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.

6A to 6E are diagrams for describing a method of manufacturing the apparatus shown in FIG. 5. 6A to 6E, the same reference numerals are used for the same members as in FIG.

Referring to FIG. 6A, after an active matrix 100 made of silicon doped with n-type is prepared, an active region may be formed in the active matrix 100 using silicon partial oxidation (LOCOS), which is a conventional device isolation process. An isolation layer 125 is formed to distinguish the active region and the field region. Subsequently, a gate 115 made of a conductive material such as polysilicon doped with impurities is formed on the active region, and then p ⁺ source 110 and drain 105 are formed using an ion implantation process. By forming the P-MOS transistors 120, M × N (M and N are natural numbers) are formed in the active matrix 100.

After forming an insulating layer 130 made of oxide on the active matrix 100 on which the P-MOS transistor 120 is formed, an upper portion of one side of the source 110 and the drain 105 is formed by using a photolithography method. Each opening is formed. Subsequently, the first metal layer 135 made of titanium, titanium nitride, tungsten, nitride, or the like is deposited on the resultant formed product, and then the first metal layer 135 is patterned by photolithography. The patterned first metal layer 135 includes a drain pad extending from the drain 105 of the P-MOS transistor 120 to a lower portion of the first anchor 171 supporting the support layer 170.

The first passivation layer 140 is formed on the first metal layer 135 and the active matrix 100. The first passivation layer 140 is formed to have a thickness of about 8000 GPa by using the silicate glass (PSG) chemical vapor deposition (CVD) method. The first protective layer 140 prevents damage to the active matrix 100 in which the P-MOS transistor 120 is embedded during the subsequent process.

The second metal layer 145 is formed on the first protective layer 140. The second metal layer 145 forms a titanium layer having a thickness of about 300 kW using a sputtering method of titanium, and then uses titanium nitride on the top of the titanium layer by about 1200 kW using a physical vapor deposition method (PVD). It is completed by forming a titanium nitride layer having a thickness. Since the light incident from the light source is incident on the second metal layer 145 not only the mirror 260 but also a portion other than the portion covered by the mirror 260, photocurrent flows through the active matrix 100, causing the device to malfunction. To prevent them. Subsequently, a portion of the second metal layer 145 in which the via hole 270 is to be formed in a subsequent process, that is, a portion in which the drain pad of the first metal layer 135 is formed is etched into the second metal layer 145. Form a hole (not shown).

The second passivation layer 150 is stacked on the second metal layer 145. The second protective layer 150 is formed to have a thickness of about 2000 kPa by using the chemical vapor deposition method. The second passivation layer 150 prevents the active matrix 100 and the results formed on the active matrix 100 from being damaged during subsequent processing.

An etch stop layer 155 is stacked on the second passivation layer 150. The etch stop layer 155 is made of low temperature oxide (LTO) such as silicon oxide (SiO ₂ ) or phosphorus pentoxide (P ₂ O ₅ ). The etch stop layer 155 is formed to have a thickness of about 0.2 to 0.8 μm at a temperature of about 350 to 450 ° C. using a low pressure chemical vapor deposition (LPCVD) method.

The first sacrificial layer 160 is stacked on the etch stop layer 155. The first sacrificial layer 160 functions to facilitate stacking of the thin films constituting the first actuating part 210 and the second actuating part 211. The first sacrificial layer 160 is formed to have a thickness of about 2.0 to 3.0 μm using the low pressure chemical vapor deposition (LPCVD) method at a temperature of about 500 ° C. or less. Subsequently, the surface of the first sacrificial layer 160 is polished using a chemical mechanical polishing (CMP) method to planarize the surface of the first sacrificial layer 160 to have a thickness of about 1.1 μm.

Subsequently, after applying and patterning a first photoresist (not shown) on top of the first sacrificial layer 160, the lower part of the first sacrificial layer 160 is used as the etching mask. The first anchor 171 and the first supporting part 170 are formed by etching the portion of the second metal layer 145 and the portions adjacent to both sides thereof by etching to expose a portion of the etch stop layer 155. The two anchors 172a and 172b are made to be formed. Therefore, the etch stop layer 155 is exposed in the shape of three squares spaced apart by a predetermined distance. Subsequently, the first photoresist is removed.

Referring to FIG. 6B, the first layer 169 is stacked on the upper portion of the etch stop layer 155 and the first sacrificial layer 160 exposed in the shape of a rectangle as described above. The first layer 169 is formed to have a thickness of about 0.1 to 1.0 μm using a low pressure chemical vapor deposition method to form a hard material such as nitride. The first layer 169 is later patterned with a support element 175, which support element 175 supports a first actuating portion 210 and a second actuating portion 211, common. The support line 174 supporting the electrode line 240, and the first anchor 171 and the second anchors 172a and 172b supporting the support layer 170 may be formed. In this case, a portion of the first layer 169 attached to the etch stop layer 155 having a center shape among the portions attached to the etch stop layer 155 exposed in the shape of the three rectangles may be the first anchor 171. The portions attached to both sides of the quadrangular etch stop layer 155 become second anchors 172a and 172b.

The lower electrode layer 179 is stacked on top of the first layer 169. The lower electrode layer 179 has a thickness of about 0.1 to 1.0 μm by sputtering or chemical vapor deposition using a metal having an electrical conductivity such as platinum (Pt), tantalum (Ta), or platinum-tantalum (Pt-Ta). Form to have. The lower electrode layer 179 is later patterned with a first lower electrode 180 and a second lower electrode 181, each corresponding to each other and having protrusions and spaced apart by a predetermined distance.

A second layer 189 made of a piezoelectric material such as PZT or PLZT is stacked on the lower electrode layer 179. The second layer 189 is formed to have a thickness of about 0.1 μm to 1.0 μm using a sol-gel method, spin coating method, or chemical vapor deposition method. Preferably, the second layer 189 is formed by spin coating PZT prepared by the sol-gel method to have a thickness of about 0.4 μm. Subsequently, the piezoelectric material constituting the second layer 189 is subjected to a heat treatment by a rapid heat treatment (RTA) method to phase change. The second layer 189 is later deformed by the first electric field generated between the first upper electrode 200 and the first lower electrode 180 and the first strained layer 190 and the second upper electrode 201. And a second strained layer 191 causing deformation by a second electric field generated between the second lower electrode 181.

The upper electrode layer 199 is stacked on top of the second layer 189. The upper electrode layer 199 is formed of a metal having electrical conductivity such as platinum, tantalum, silver (Ag), or platinum-tantalum to have a thickness of about 0.1 to 1.0 μm using a sputtering method or a chemical vapor deposition method. The upper electrode layer 199 is later patterned with a first upper electrode 200 and a second upper electrode 201 which are respectively applied with a second signal (bias signal) and are spaced apart by a predetermined distance.

Referring to FIG. 6C, after applying and patterning a second photoresist (not shown) on the upper electrode layer 199, each of the upper electrode layers 199 may be squared using the second photoresist as a mask. The first upper electrode 200 and the second upper electrode 201 are formed in the shape of a flat plate, preferably in the form of a rectangular flat plate and separated from each other by a predetermined distance (see FIG. 4). A second signal is applied to the first upper electrode 201 and the second upper electrode 201 through a common electrode line 240 formed later from the outside, respectively. Subsequently, the second photoresist is removed.

Subsequently, the second layer 189 is patterned in the same manner as the method of patterning the upper electrode layer 199 into the first upper electrode 200 and the second upper electrode 201, and each has a rectangular plate shape. The first strained layer 190 and the second strained layer 191 are formed to be separated from each other by a predetermined distance and formed side by side. In this case, as shown in FIG. 4, the first strained layer 190 and the second strained layer 191 have a rectangular flat shape slightly wider than the first upper electrode 200 and the second upper electrode 201, respectively. It is patterned to have

Subsequently, the first lower electrode 180 and the second lower electrode 181 are formed by patterning the lower electrode layer 179 in the same manner as the method of patterning the upper electrode layer 199. The first lower electrode 180 has a shape of a square plate having a protrusion formed at one side thereof, that is, a 'L' shape on the mirror, and the second lower electrode 182 has a protrusion at one side corresponding to the first lower electrode 181. It has the shape of the rectangular plate formed, that is, the shape of the 'L'. In addition, when the lower electrode layer 179 is patterned, the common electrode line 240 formed in a direction orthogonal to the first lower electrode 180 and the second lower electrode 181 on one side of the first layer 169. ) Is formed simultaneously with the first lower electrode 180 and the second lower electrode 181. Each of the first lower electrode 180 and the second lower electrode 181 has a slightly larger area than the first strained layer 190 and the second strained layer 191, and the common electrode line 240 is formed later. A portion of the first lower electrode 180 and the second lower electrode 181 is spaced apart from the first lower electrode 180 by a predetermined distance. Accordingly, the first actuating part 210 including the first upper electrode 200, the first strained layer 190, and the first lower electrode 180, the second upper electrode 201, and the second strained layer ( The second actuating part 211 including the 191 and the second lower electrode 181 is completed.

Subsequently, the first layer 169 is patterned to form a support element 175 comprising a support layer 170, a support line 174, a first anchor 171, and second anchors 172a, 172b. . At this time, both sides of the portion of the first layer 169 contacting the etch stop layer 155 exposed in the shape of the three quadrangles are second anchors 172a and 172b, and the center portion of the first anchor 171 is located. ) Each of the first anchor 171 and the second anchors 172a and 172b has a rectangular box shape, and a hole of the second metal layer 145 is formed under the first anchor 171 (see FIG. 4). ).

The support layer 170 has a rectangular annular shape, preferably, a rectangular annular shape and is integrally formed with the supporting line 174. In this state, when the first sacrificial layer 160 is later removed, a supporting element 175 having a shape as shown in FIG. 4 is formed. That is, the support layer 170 has a rectangular annular shape and is integrally formed with the support line 174 on one side of the support line 174 along a direction perpendicular to the support plane 174 in the same plane orthogonal to the support line 174. A first anchor 171 is integrally formed with the two arms in a lower portion between two arms horizontally extending in a direction orthogonal to the support line 174 of the supporting layer 170 having a shape, thereby preventing the etch stop layer 155. Two second anchors 172a and 172b are respectively formed integrally with the two arms and attached to the etch stop layer 155 at the outer lower portion of the two arms. The first anchor 171 and the second anchors 172a and 172b which together support the support layer 170 are formed under a portion of the support layer 170 adjacent to the support line 174.

The first actuating part 210 and the second actuating part 211 are formed parallel to each other on top of two arms horizontally extending in a direction orthogonal to the support line 174 of the support layer 170. Accordingly, the first anchor 171 is formed between the first actuating part 210 and the second actuating part 211, and the second anchors 172a and 172b are respectively the first actuating part 210. It is formed on the outer side of the and the second actuating portion 211.

Referring to FIG. 6D, a third upper portion of the support element 175 including the support layer 170 and the support line 174 and a top of the first actuating portion 210 and the second actuating portion 211 are provided. A photoresist (not shown) is applied and patterned to expose the first upper electrode 200 and the second upper electrode 201 from the common electrode line 240 formed on the support line 174. At this time, the protrusion of the first lower electrode 180 and the protrusion of the second lower electrode 181 are also exposed together from the first anchor 171.

Subsequently, silicon oxide (SiO ₂ ) or phosphorus pentoxide, which is amorphous silicon or a low temperature oxide, is exposed in the exposed portions from the common electrode line 240 to the first upper electrode 200 and the second upper electrode 201. ₂ O ₅ ), and the like, by depositing and patterning the first insulating layer from a portion of the first upper electrode 200 to a portion of the support layer 170 through the first strained layer 190 and the first lower electrode 180. And a second insulating layer 221 from a portion of the second upper electrode 201 to a portion of the support layer 170 through the second deformable layer 191 and the second lower electrode 181. Form. The first insulating layer 220 and the second insulating layer 221 are formed to have a thickness of about 0.2 to 0.4 µm, and preferably about 0.3 µm, respectively, using a low pressure chemical vapor deposition (LPCVD) method.

Subsequently, the first anchor 171 and the etch stop layer (from the central upper portion of the first anchor 171, which is a portion where the hole 147 of the second metal layer 145 and the drain pad of the first metal layer 135 are formed below). 155, the second protective layer 150, and the first protective layer 140 are etched to form the via hole 270 to the drain pad, and then the via contact 280 is formed in the via hole 270. The first lower electrode connecting member 290 and the second lower electrode connecting member 291 are formed from the via hole 270 to the protrusion of the first lower electrode 180 and the protrusion of the second lower electrode 181, respectively. (See FIG. 4). At the same time, the first upper electrode connecting member 230 and the second upper electrode 201 from the first upper electrode 200 to the common electrode line 240 through a part of the first insulating layer 230 and the support layer 170. The second upper electrode connecting member 231 is formed from the second insulating layer 231 and the support layer 170 to the common electrode line 240.

The via contact 280, the first lower electrode connecting member 290, the second lower electrode connecting member 291, the first upper electrode connecting member 230, and the second upper electrode connecting member 231 are each platinum or Platinum-tantalum is deposited using a sputtering method or a chemical vapor deposition method to have a thickness of about 0.1 to 0.2 μm, and then the deposited metal is patterned. The first upper electrode connecting member 230 and the second upper electrode connecting member 231 connect the first upper electrode 200, the second upper electrode 201, and the common electrode line 240, respectively.

The protrusion of the first lower electrode 180 is connected to the drain pad of the first metal layer 135 through the first lower electrode connecting member 290 and the via contact 280, and the protrusion of the second lower electrode 181. The second lower electrode connecting member 291 and the via contact 280 are connected to the drain pad.

Referring to FIG. 6E, in order to form the second sacrificial layer 300, amorphous silicon is first formed on the first actuating part 210, the second actuating part 211, and the support element 175. ) Is deposited to a thickness of about 1000 to 3000 kPa using a plasma enhanced chemical vapor deposition method to form an amorphous silicon layer 300a. Since the amorphous silicon has difficulty in laminating the thickness resulting from the active matrix 100 and having a sufficient thickness to be flattened using a chemical mechanical polishing method, the polycrystalline silicon is deposited on the amorphous silicon layer 300a at a low pressure chemical vapor phase. The second sacrificial layer 300 is formed by forming a polycrystalline silicon layer 300b to have a height sufficient to cover the first actuating part 210 and the second actuating part 211 using an LPCVD method. Complete Since such amorphous silicon has excellent adhesion to metals such as platinum constituting the first upper electrode 200, the first lower electrode 180, and the second upper electrode 201 and the second lower electrode 181. In contrast, when the polysilicon layer 300b is formed on the amorphous silicon layer 300a, the polysilicon layer 300b can be remarkably uniform and easily formed when the polycrystalline silicon is deposited only on the metal layer. Therefore, the adhesion and flatness of the second sacrificial layer 300 including the amorphous silicon layer 300a and the polycrystalline silicon layer 300b can be greatly improved.

Subsequently, the surface of the second sacrificial layer 300 is planarized by using a chemical mechanical polishing (CMP) method such that an upper portion of the second sacrificial layer 300 has a flat surface. Subsequently, the second sacrificial layer 300 is patterned to form the mirrors 260 and the posts 250, thereby forming parallel to the support lines 174 of the support layers 170 having the rectangular ring formation without being adjacent to each other. Expose part of the part. Subsequently, a metal such as aluminum (Al) having reflective properties is deposited on a portion of the exposed support layer 170 and the second sacrificial layer 300 by using a sputtering method or a chemical vapor deposition method. By patterning to form a mirror 260 having a shape of a square plate and a post 250 for supporting the mirror 260 at the same time.

In addition, the first sacrificial layer 160 and the second sacrificial layer 300 are simultaneously removed using xenon fluoride (XeF ₂ ) or bromine fluoride (BrF ₂ ), and the cleaning and drying treatments are performed. The AMA element as shown is completed. As described above, when the second sacrificial layer 300 is removed, the second air gap 310 is formed at the position of the second sacrificial layer 300, and when the first sacrificial layer 160 is removed, the first sacrificial layer 160 is removed. The first air gap 165 is formed at the position of.

In the above-described thin film type optical path control apparatus according to the present invention, the first signal transmitted from the outside is the MOS transistor 120 embedded in the active matrix 100, the drain pad of the first metal layer 135, and the via contact 280. And a first lower electrode 180 applied through the first lower electrode connection member 290 and connected to the MOS transistor 120, the drain pad of the first metal layer 135, the via contact 280, and the second lower electrode. The first signal is also applied to the second lower electrode 181 through the member 291. At the same time, a second signal is applied to the first upper electrode 200 through the common electrode line 240 and the first upper electrode connecting member 230 from the outside, and the common electrode line 240 and the second upper electrode 201 are also applied to the first upper electrode 200. The second signal is applied through the second upper electrode connecting member 231. Therefore, a first electric field is generated between the first upper electrode 200 and the first lower electrode 180 according to the potential difference, and the first electric field is generated between the second upper electrode 201 and the second lower electrode 181. 2 An electric field is generated. The first strained layer 190 formed between the first upper electrode 200 and the first lower electrode 180 causes deformation by the first electric field, and simultaneously the second upper electrode 201 by the second electric field. And the second strained layer 191 formed between the second lower electrode 181 cause deformation.

As the first strained layer 190 and the second strained layer 191 contract in a direction orthogonal to the first electric field and the second electric field, respectively, the first actuator 210 including the first strained layer 190. ) And the second actuating part 211 including the second deformable layer 191 are each bent at a predetermined angle. As the first actuating part 210 and the second actuating part 211 are bent at a predetermined angle, the lower support layer 170 is also bent at a predetermined angle.

The mirror 260 reflecting the light incident from the light source is supported by the post 250 and is formed on the first actuator 210 and the second actuator 211, and thus, together with the support layer 170. Incline Accordingly, the mirror 260 reflects incident light at a predetermined angle, and the reflected light passes through the slit to form an image on the screen.

According to the optical path control apparatus and manufacturing method according to the present invention, there is provided a support element, an amorphous silicon layer having excellent adhesion to a metal on top of a first and second actuating portion, and a second silicon layer deposited on the top. By forming the sacrificial layer, the second sacrificial layer can be easily formed and the uniformity and flatness of the second sacrificial layer can be improved. Therefore, the horizontality of the mirror formed on the upper portion of the second sacrificial layer can be improved, and thus the image quality of the image projected onto the screen 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 (3)

Providing an active matrix including a first metal layer having a MOS transistor embedded therein and having a drain pad extending from the drain of the transistor; Forming and patterning a first sacrificial layer using polycrystalline silicon on top of the active matrix, and then forming support means on top of the first sacrificial layer; A second actuator including a first actuating part including a first lower electrode, a first deforming layer, and a first upper electrode, and a second lower electrode, a second deforming layer, and a second upper electrode on the support means; Forming a part; Forming a second sacrificial layer comprising forming an amorphous silicon layer and forming a polycrystalline silicon layer on top of the support means, the first actuating portion and the second actuating portion; Forming a mirror on top of the second sacrificial layer; And And removing the first sacrificial layer and the second sacrificial layer. The method of claim 1, wherein the forming of the amorphous silicon layer comprises depositing at a thickness of about 1000 to 3000 Pa using a plasma enhanced chemical vapor deposition method. The method of claim 1, wherein forming the polycrystalline silicon layer further includes forming the polycrystalline silicon layer using a low pressure chemical vapor deposition method, and then planarizing the surface of the polycrystalline silicon layer using a chemical mechanical polishing method. The manufacturing method of the thin film type optical path control apparatus characterized by the above-mentioned.