KR20000044208A - Thin film micromirror array-actuated device and manufacturing method thereof - Google Patents

Abstract

PURPOSE: A manufacturing method of the TMA device is provided to prevent the bending of the actuator in the upward or downward direction by making the actuator in a strong rib formation. CONSTITUTION: A device comprises an active matrix(100), a substrate(101), a first sacrificial layer(160), a supporting layer(170) a first metal layer(135), a first protection layer(140), a second metal layer(145), a second protection layer(150), and an etching preventing layer(155). A manufacturing method comprises a step of providing the active matrix including the first metal layer which has the drain pad extended from the drain of the transistor; a step of exposing both sides of the drain pad; a step of forming a plurality of holes on the upper part of the exposed active matrix; a step of forming a supporting instrument including the second anchor, first anchor, supporting layer, and a supporting line; a step of forming a common electrode line on the upper part of the supporting line; and a step of forming a mirror on the upper part of the actuator.

Description

Thin film type optical path control device and its manufacturing method

The present invention relates to a thin film type optical path control apparatus using an Actuated Mirror Array (AMA) and a method for manufacturing the same, and more particularly, to a thin film type optical path control apparatus capable of preventing initial tilting of an actuator and a method of manufacturing the same. will be.

Optical path control devices or spatial light modulators for projecting optical energy onto the 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 type image display device and a projection type image display device according to a method of displaying optical energy on a screen.

An example of a direct view image display device is a CRT (Cathode Ray Tube), which is a so-called CRT device, which has excellent image quality but increases in weight and volume as the size of the screen increases, leading to increased manufacturing costs. There is. Projection type image display devices include liquid crystal display (LCD), deformable mirror device (DMD) and AMA. Such projection image display apparatuses can be further divided into two groups according to their optical characteristics. That is, devices such as LCDs can be classified as transmit light modulators, while DMD and AMA can be classified as reflected 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, the light efficiency is low due to the polarity of the light, there is a problem inherent in the liquid crystal material, for example, 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 in the range of 1-2% and requires 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.

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, processes it using a sawing method, and applies a mirror to the top. 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 deformation layer is slow.

Accordingly, a thin film type optical path control device 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. 98-26319 filed by the applicant of the Korean Patent Office on June 30, 1998 have.

FIG. 1 is a perspective view of the thin film type optical path control device, and FIG. 2 is a cross-sectional view of the device of FIG. 1 taken along line A ₁ A ₂ .

1 and 2, the thin film type optical path control device includes an active matrix 16, a support element 18, an actuator 31, and a mirror 41.

Referring to FIG. 2, the active matrix 16 includes a substrate 1 having M × N (M, N is a natural number) MOS transistors 5, a drain 2 and a source of the MOS transistors 5. First metal layer 8 formed on top of substrate 1 extending from (3), first protective layer 9 formed on top of first metal layer 8, second metal layer 10, second protection Layer 12 and anti-etching layer 13.

Referring to FIG. 1, the support element 18 comprises a support layer 19, a support line 20, a first anchor 21 and second anchors 22a, 22b. The support line 20 and the support layer 19 are horizontally formed on the etch stop layer 13 via the first air gap 15. The common electrode line 32 is formed on the support line 20. The support layer 19 is integrally formed along the direction orthogonal to the support line 20 in the shape of a rectangular ring on the same plane. A first anchor 21 is integrally formed with the two arms and attached to the etch stop layer 13 at a lower portion between two arms horizontally extending in a direction orthogonal to the support line 20 of the support layer 19. Two second anchors 22a and 22b are integrally formed with the two arms and attached to the etch stop layer 13 at the outer lower portion of the two arms. The support layer 19 is supported by the first anchor 21 in the center portion and supported by both anchors 22a and 22b. The first anchor 21 is formed on a portion of the etch stop layer 13 where the drain pad of the first metal layer 8 is located. A via hole 38 is formed from the first anchor 21 to the drain pad of the first metal layer 8.

The actuator 31 includes a lower electrode 24, a first strained layer 26, a second strained layer 27, a first upper electrode 29, and a second upper electrode 30. The lower electrode 24 has a mirror-shaped 'c' shape spaced apart from the support line 20 by a predetermined distance, and protruding portions are stepped toward the first anchor 21 on one side of the lower electrode 24. Are formed corresponding to each other. The protrusions of the lower electrode 24 extend to the periphery of the via hole 38 formed in the first anchor 21, respectively. The via contact 39 is formed from the drain pad of the first metal layer 8 to the protrusions of the lower electrode 24 through the via hole 38 to connect the drain pad and the lower electrode 24. The two arms of the lower electrode 24 each have the shape of a rectangular plate, and the first and second deformable layers 26 and 27 respectively have the shape of the rectangular plate having a smaller area than the two arms of the lower electrode 24. It is formed on top of the arms of the lower electrode 24. In addition, the first and second upper electrodes 29 and 30 have a shape of a rectangular plate having a smaller area than the first and second deformable layers 26 and 27, respectively, and the first and second deformable layers 26 and 27. It is formed at the top of the.

The first insulating layer 34 is formed from one side of the first upper electrode 29 to a part of the supporting layer 19, and the first insulating layer 34 and the supporting layer 19 from one side of the first upper electrode 29. The first upper electrode connecting member 36 is formed up to the common electrode line 32 through a portion of the upper electrode connecting member 36. In addition, a second insulating layer 35 is formed from one side of the second upper electrode 30 to a part of the support layer 19, and the second insulating layer 35 and the supporting layer (from one side of the second upper electrode 30) A second upper electrode connecting member 37 is formed up to the common electrode line 32 through a portion of 19.

A mirror 41 is formed at a portion of the mirror-shaped 'c'-shaped lower electrode 24 in which the first and second upper electrodes 29 and 30 are not formed, that is, parallel to the support line 20. A supporting post 40 is formed. The mirror 41 is centrally supported by the post 40, and both sides thereof are horizontally formed on the upper portion of the actuator 31 via the second air gap 43. The mirror 41 reflects light incident from a light source (not shown) at a predetermined angle.

Hereinafter, the manufacturing method of the above-described thin film type optical path control apparatus will be described.

3A to 3C are diagrams for describing a method of manufacturing the apparatus shown in FIG. 2.

Referring to FIG. 3A, a device isolation layer 6 is formed on a substrate 1, which is an n-type doped silicon wafer, by using a silicon partial oxidation method (LOCOS) to distinguish an active region from a field region. Subsequently, a gate 4 made of a conductive material such as polysilicon is formed on the active region, and then p ⁺ source 3 and drain 2 are formed by an ion implantation process, thereby forming M on the substrate 1. N (M and N are natural numbers) P-MOS transistors 5 are formed.

After the insulating film 7 made of oxide is formed on the P-MOS transistor 5 formed thereon, openings are formed to expose the upper portions of one side of the source 3 and the drain 2 by photolithography. . Subsequently, a first metal layer 8 made of titanium, titanium nitride, tungsten, nitride, or the like is deposited on top of the resultant product in which the openings are formed, and then the first metal layer 8 is patterned. The patterned first metal layer 8 includes a drain pad extending from the drain 2 of the P-MOS transistor 5 to the bottom of the first anchor 21.

A first protective layer 9 is formed on the first metal layer 8 and on top of the substrate 1 to prevent damage to the substrate 1 in which the P-MOS transistor 5 is embedded during subsequent processing. The first protective layer 9 is formed of a silicate glass (PSG) having a thickness of 8000 kPa by chemical vapor deposition (CVD) method.

The second metal layer 10 is formed on the first protective layer 9. The second metal layer 10 is formed by sputtering titanium to form a titanium layer with a thickness of 300 kV, and then forming a titanium nitride layer having a thickness of 1200 kV on the titanium layer by physical vapor deposition (PVD). Is completed. The second metal layer 10 enters the incident light not only to the mirror 41 but also to a portion other than the portion covered by the mirror 41, so that photocurrent flows through the active matrix 16 to prevent the device from malfunctioning. Subsequently, a hole (not shown) in the second metal layer 10 is etched by etching a portion of the second metal layer 10 in which the drain pad of the first metal layer 8 is formed below the second metal layer 10 in consideration of the position where the via hole 38 is to be formed later. Not formed).

The second protective layer 12 is stacked on the second metal layer 10. The second protective layer 12 is formed of the silicate glass to have a thickness of about 2000 kPa using a chemical vapor deposition method. The second protective layer 12 prevents the substrate 1 and the resulting products formed on the substrate 1 from being damaged during subsequent processing.

On top of the second passivation layer 12 is an etch stop layer 13 that prevents the second passivation layer 12 and the resulting products on the substrate 1 from being etched during the subsequent etching process. The etch stop layer 13 is made of low temperature oxide (LTO) such as silicon oxide (SiO ₂ ) or phosphorus pentoxide (P ₂ O ₅ ). The etch stop layer 13 is formed to have a thickness of 0.2 to 0.8 mu m at 350 to 450 DEG C using a low pressure chemical vapor deposition (LPCVD) method. Accordingly, the active matrix 16 including the substrate 1, the first metal layer 8, the first protective layer 9, the second metal layer 10, the second protective layer 12, and the etch stop layer 13. Is completed.

The first sacrificial layer 14 is stacked on the etch stop layer 13. The first sacrificial layer 14 is formed of polysilicon to have a thickness of 2.0 to 3.0 μm by low pressure chemical vapor deposition (LPCVD). Subsequently, the surface of the first sacrificial layer 14 is polished by chemical mechanical polishing (CMP) to planarize the surface of the first sacrificial layer 14 to have a thickness of 1.1 mu m. Subsequently, after applying and patterning a first photoresist (not shown) on top of the first sacrificial layer 14, the second photoresist is used as a mask, and a second photoresist is disposed below the first sacrificial layer 14. The first anchor 21 and the second anchors supporting the supporting layer 19 to be formed later by etching the portions in which the holes of the metal layer 12 and the portions adjacent to both sides are etched to expose a portion of the etch stop layer 13. Create a position at which 22a, 22b will be formed and remove the first photoresist. Accordingly, the etch stop layer 13 is exposed in the shape of three squares spaced apart by a predetermined distance.

The first layer 17 is stacked on the exposed etch stop layer 13 and the first sacrificial layer 14 as described above. The first layer 17 is formed to have a thickness of 0.1 to 1.0 mu m by low pressure chemical vapor deposition (LPCVD). The lower electrode layer 23 is stacked on top of the first layer 17. The lower electrode layer 23 is formed to have a thickness of 0.1 to 1.0 μm using a metal such as platinum (Pt), tantalum (Ta), or platinum-tantalum (Pt-Ta) by sputtering or chemical vapor deposition.

The second layer 25 made of a piezoelectric material is stacked on the lower electrode layer 23. The second layer 25 is formed by spin coating PZT prepared by the sol-gel method to have a thickness of 0.4 μm. Subsequently, the piezoelectric material constituting the second layer 25 is subjected to heat treatment by rapid thermal treatment (RTA) to cause phase shift.

The upper electrode layer 28 is stacked on top of the second layer 25. The upper electrode layer 28 is formed of a metal such as platinum, tantalum, silver, or platinum-tantalum to have a thickness of 0.1 to 1.0 mu m using a sputtering method or a chemical vapor deposition method.

Referring to FIG. 3B, after applying and patterning a second photoresist (not shown) on the upper electrode layer 28, the upper electrode layer 28 is formed into a rectangular flat plate using the second photoresist as a mask. And patterning the first and second upper electrodes 29 and 30 formed in parallel with each other, and then removing the second photoresist. A second signal (bias signal) is applied to the first and second upper electrodes 29 and 30 through a common electrode line 32 formed later from the outside, respectively.

Subsequently, the second layer 25 is patterned in the same manner as the patterning of the upper electrode layer 28 to form first and second strained layers 26 and 27, each having a shape of a rectangular flat plate and formed in parallel with each other. do. In this case, as shown in FIG. 1, the first and second strained layers 26 and 27 are patterned to have a rectangular plate shape slightly wider than that of the first and second upper electrodes 29 and 30, respectively.

Subsequently, the lower electrode layer 23 has a mirror-shaped 'c' shape with respect to the support line 20 formed later by patterning the lower electrode layer 23, and has a lower electrode 24 having protrusions formed stepped toward the first anchor 21. ). In this case, the two arms of the lower electrode 24 have the shape of a rectangular flat plate having a larger area than the first and second deforming layers 26 and 27, respectively. In addition, when the lower electrode layer 23 is patterned, the common electrode line 32 is formed simultaneously with the lower electrode 24 in a direction perpendicular to the lower electrode 24 on one side of the first layer 17. The common electrode line 32 is formed to be spaced apart from the lower electrode 24 by a predetermined distance on the support line 20 formed later. Thus, the actuator 31 including the first and second upper electrodes 29 and 30, the first and second strained layers 26 and 27, and the lower electrode 24 is completed.

The first layer 17 is then patterned to form a support element 18 comprising a support layer 19, a support line 20, a first anchor 21 and second anchors 22a, 22b. At this time, both sides of the portion of the first layer 17 contacting the etch stop layer 13 exposed in the three quadrangles are second anchors 22a and 22b and the center portion is the first anchor 21. . The first anchor 21 and the second anchors 22a and 2b each have a rectangular box shape, and below the first anchor 21, holes of the second metal layer 10 and holes of the first metal layer 8 are formed. A drain pad is formed. Therefore, the first anchor 21 is formed below the lower electrode 24, and the second anchors 22a and 22b are formed below the outer side of the lower electrode 24, respectively.

Subsequently, a third photoresist (not shown) is applied and patterned on the support element 18 and the actuator 31 to form first and second upper portions from the common electrode line 32 formed on the support line 19. A part of the electrodes 29 and 30 are exposed respectively. At this time, even the protrusions of the lower electrode 24 are exposed together from the first anchor 21.

Subsequently, silicon oxide or phosphorus pentoxide, which is amorphous silicon or a low temperature oxide, is deposited and patterned on the exposed portion, so that a portion of the first upper electrode 29 is formed through the first strained layer 26 and the lower electrode 24. The first insulating layer 34 is formed to a part of the support layer 19, and at the same time, a part of the support layer 19 through the second strained layer 27 and the lower electrode 24 from a part of the second upper electrode 30. Until the second insulating layer 35 is formed. The first and second insulating layers 34 and 35 are formed to have a thickness of 0.2 to 0.4 탆, respectively, by low pressure chemical vapor deposition (LPCVD).

Next, the first anchor 21, the etch stop layer 13, and the first anchor 21 are formed from a central portion of the first anchor 21, which is a portion where the hole of the second metal layer 10 and the drain pad of the first metal layer 8 are formed below. After the second protective layer 12 and the first protective layer 9 are etched to form the via hole 38 to the drain pad, the via contact is extended from the drain pad to the protrusions of the lower electrode 24 through the via hole 38. 39). At the same time, the first upper electrode connecting member 36 and the second upper electrode 30 extend from the first upper electrode 29 to the common electrode line 32 through a part of the first insulating layer 34 and the support layer 19. The second upper electrode connecting member 37 is formed from the second insulating layer 35 and the support layer 19 to the common electrode line 32.

The via contact 39 and the first and second upper electrode connecting members 36 and 37 are deposited by depositing platinum or platinum-tantalum to have a thickness of 0.1 to 0.2 μm by sputtering or chemical vapor deposition. Patterned metal is formed. The first and second upper electrode connecting members 36 and 37 connect the first and second upper electrodes 29 and 30 to the common electrode line 32, respectively, and the lower electrode 24 connects the via contact 39. It is connected to the drain pad through.

Referring to FIG. 3C, a second sacrificial layer 42 is formed by spin coating an acfloflo having excellent deposition flatness on top of the actuator 31 and the support element 18. Subsequently, in order to form the mirror 41 and the post 40, after applying and patterning a fourth photoresist (not shown) on the second sacrificial layer 42, the fourth photoresist is used as a mask. By etching a portion of the second sacrificial layer 42, a portion of the mirror-shaped 'c' shaped lower electrode 24 which is not adjacent to the support line 20 but formed in parallel (ie The first and second upper electrodes 29 and 30 are not formed).

Next, aluminum is deposited on a portion of the exposed lower electrode 24 and the second sacrificial layer 42 to a thickness of 0.1 to 1.0 μm using a sputtering method or a chemical vapor deposition method. Patterning to form a mirror 41 having a rectangular flat plate shape and a post 40 for supporting the mirror 41 at the same time. After the second sacrificial layer 42 and the fourth photoresist are removed by plasma ashing, the first sacrificial layer 14 is replaced with xenon fluoride (XeF ₂ ) or bromine fluoride (BrF ₂ ). Removal, and washing and drying treatments are performed to complete the AMA device as shown in FIG.

However, in the above-described thin film type optical path control device, if the first and second sacrificial layers are removed after the actuator is formed, the thin films constituting the actuator exert a force in the upward direction or downward direction due to the residual stress difference. Even when the driving voltage is not applied, the initial bending of the actuator is caused when the actuator is inclined upward or downward by about 3 to 5 degrees. As such, when the initial warpage occurs in the actuator, it becomes difficult to maintain the reflection angle of the mirror on the upper part of the actuator, resulting in a deterioration in the image quality of the image projected on the screen.

Accordingly, it is an object of the present invention to provide a thin film type optical path control device and a method for manufacturing the same, which can prevent the initial bending of the actuator by having the structure resistant to the deformation stress.

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

FIG. 2 is a cross-sectional view of the apparatus shown in FIG. _{1 taken along} lines A ₁ -A ₂ .

3A to 3C are manufacturing process diagrams of the apparatus shown in FIG.

Figure 4 is a perspective view of a thin film type optical path control apparatus according to the present invention.

5 is a cross-sectional view of the apparatus of FIG. 4 taken along line B ₁ -B ₂ .

FIG. 6 is a cross-sectional view of the device of FIG. 4 taken along line C ₁ -C _2. FIG.

7A to 11B are manufacturing process diagrams of the apparatus shown in FIGS. 5 and 6.

<Explanation of symbols for main parts of the drawings>

100: active matrix 101: substrate

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 element

180: lower electrode 190, 191: first and second strained layers

200, 201: first and second upper electrodes 210: actuators

220, 221: first and second insulating layers

230 and 231: first and second upper electrode connecting members

250: Post 260: Mirror

270: Beer Hall 280: Beer Contact

300: second sacrificial layer

In order to achieve the above object of the present invention, the present invention provides a thin film type optical path control device including an active matrix, a support element, an actuator and a mirror. The active matrix having the MOS transistor embedded therein includes a first metal layer having a drain pad extending from the drain of the transistor. The support element is formed on the support line formed on top of the active matrix, the support line is formed integrally with the support line and has a rectangular ring shape, and the support layer in contact with the active matrix of the lower portion of the support layer adjacent to the support line, respectively to support the support layer A first anchor and a second anchor. A plurality of grooves are formed in each of two arms horizontally extending in a direction orthogonal to the support line among the support layers having the shape of the square ring. The actuator is formed on the support layer and has a lower electrode having a mirror-shaped 'C' shape with respect to the support line, a first deformed layer formed on one side of the lower electrode, and a second deformed layer formed on the other side of the lower electrode. And a first upper electrode formed on the first strained layer, and a second upper electrode formed on the second strained layer. A plurality of grooves are formed in the lower electrode, the first and second deformable layers, and the first and second upper electrodes, respectively, in the shape of the upper limb support layer. The mirror is supported by a post formed on a parallel portion of the support layer spaced apart from the support line and formed on top of the actuator.

In addition, in order to achieve the above object of the present invention, the present invention provides a step of providing an active matrix comprising a first metal layer having a drain pad embedded in the MOS transistor and extending from the drain of the transistor, on top of the active matrix After forming a first sacrificial layer, patterning the first sacrificial layer to expose portions of the active pad where the drain pads are formed and both sides of the portions where the drain pads are formed, the exposed active matrix and the first sacrificial layer; Forming a plurality of grooves on the first layer by etching a portion of the first layer after forming the first layer on the upper layer, the lower electrode layer on the first layer on which the plurality of grooves are formed, and the second layer Forming a layer and an upper electrode layer, patterning the upper electrode layer, the second layer, and the lower electrode layer to form first and second upper electrodes; Forming an actuator including a pole, first and second deformable layers, and a lower electrode; patterning the first layer to form a support line formed on the active matrix; Forming support means including a support layer having a plurality of grooves formed at both sides and first and second anchors respectively contacting the active matrix below a portion of the support layer adjacent to the support line; It provides a method of manufacturing a thin film type optical path control device comprising the step of forming a common electrode line on the upper portion, and forming a mirror on the upper portion of the actuator.

According to the present invention, two arms extending horizontally in a direction orthogonal to the support line of the rectangular-shaped support layer are etched to a predetermined depth to form a plurality of grooves, and then the lower electrodes, the first and the second electrodes thereon. The strained layer and the first and second upper electrodes are formed. Since the lower electrode, the first and second strained layers, and the first and second upper electrodes are stacked on the support layer on which the plurality of grooves are formed, a plurality of grooves are formed along the shape of the support layer. Accordingly, the actuator including the lower electrode, the first and second strained layers and the first and second upper electrodes, each of which has a plurality of grooves, has a rib-shaped structure that is strong in strain stress. Therefore, it is possible to prevent the initial bending of the actuator, which is a phenomenon in which the actuator is bent upward or downward even without a driving voltage due to deformation stress such as residual stress generated during the formation of the actuator.

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

Figure 4 shows a perspective view of the thin film type optical path control apparatus according to the present invention, Figure 5 shows a cross-sectional view of the device of Figure 4 cut line B ₁ -B ₂ , Figure 6 shows the device of Figure 4 C ₁ cut in the cross-sectional view taken along the line ₂ -C illustrates.

4 and 5, the thin film type optical path control apparatus according to the present invention includes an active matrix 100, a support element 175 formed on the active matrix 100, and an actuator formed on the support element 175. 210, and a mirror 260 formed on the actuator 210.

5 and 6, the active matrix 100 includes a substrate 101 having M × N (M, where N is a natural number) P-MOS transistors 120 and the P-MOS transistors 120. A first metal layer 135 formed on the substrate 101, a first protective layer 140 formed on the first metal layer 135, and a first protective layer extending from the drain 105 and the source 110; The second metal layer 145 formed on the upper portion of the 140, the second protective layer 150 formed on the second metal layer 145, and the etch stop layer 155 formed on the second protective layer 150 are included. do. The first metal layer 135 includes a drain pad extending from the drain 105 of the P-MOS transistor 120 to transmit a first signal (image signal), and the second metal layer 145 includes a titanium layer and nitride. It consists of a titanium layer.

4 and 6, the support element 175 includes a support layer 170, a support line 174, a first anchor 171, and second anchors 172a and 172b. The support line 174 and the support layer 170 are horizontally formed on the etch stop layer 155 via 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 ring shape, preferably a rectangular ring shape, and is integrally formed with the support line 174 in a direction orthogonal to the support line 174 on the same plane. A plurality of grooves are formed in the two arms horizontally extending in a direction orthogonal to the support line 174 of the square ring-shaped support layer 170. As these grooves are formed in the arms of the support layer 170, the support layer 170 has a strong structure against deformation stress acting in a direction perpendicular to the support line 174.

A first anchor 171 is integrally formed with the two arms and attached to the etch stop layer 155 at lower portions between the arms of the support layer 170, and two second anchors are disposed below the outer sides of the two arms. 172a and 172b are integrally formed with the two arms and attached to the etch stop layer 155.

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 by the first anchor 171 in the center portion and supported by both anchors 172a and 172b.

The first anchor 171 is formed on a portion of the etch stop layer 155 where the drain pad of the first metal layer 135 is located. 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 147 of the second metal layer 145, and the first passivation layer 140. The via hole 270 is formed to the drain pad of the.

The actuator 210 is formed on the support layer 170 in the shape of a mirror 'C' with respect to the support line 174. The actuator 210 includes a lower electrode 180, a first strained layer 190, a second strained layer 191, a first upper electrode 200, and a second upper electrode 201. The lower electrode 180 has a mirror-shaped 'c' shape spaced apart from the support line 174 by a predetermined distance, and is stepped toward the first anchor 171 at both sides of one side of the lower electrode 180. The protrusions are formed corresponding to each other. The protrusions of the lower electrode 180 extend to the periphery of the via hole 270 formed in the first anchor 171, respectively.

The via contact 280 is formed from the drain pad of the first metal layer 135 to the protrusion of the lower electrode 180 through the via hole 280 to electrically connect the drain pad and the lower electrode 180.

Two arms of the mirror-shaped 'c'-shaped lower electrode 180 formed on the support layer 170 have a shape of a rectangular plate on which a plurality of grooves are formed. That is, since the arms of the lower electrode 180 are formed along the shapes of the arms of the support layer 170 formed thereunder, the arms of the lower electrode 180 may have a plurality of structures such that the lower electrodes 180 have a strong structure against deformation stress. Grooves are formed.

The first and second deformable layers 190 and 191 have a shape of a rectangular flat plate having a narrower area than the two arms of the lower electrode 180, respectively, and are formed on the two arms of the lower electrode 180. Since the first and second strained layers 190 and 191 are also formed on the upper portions of the arms of the lower electrode 180, the first and second strained layers 190 and 191 also follow the shapes of the arms of the lower electrode 180. Each of the plurality of grooves is formed.

The first and second upper electrodes 200 and 201 have a shape of a rectangular flat plate having a smaller area than the first and second deformable layers 190 and 191, respectively, and have an upper portion of the first and second deformable layers 190 and 191. Is formed. Similar to the first and second strained layers 190 and 191, a plurality of first and second upper electrodes 200 and 201 may have a structure in which the first and second upper electrodes 200 and 201 have a structure resistant to strain stress. Grooves are formed. Accordingly, the actuator 210 including the lower electrode 180, the first and second strained layers 190 and 191, and the first and second upper electrodes 200 and 201 may have a length of the actuator 210 as a whole. It has a rib-shaped structure that is strong against deformation stress acting in the direction.

The first insulating layer 220 is formed from one side of the first upper electrode 200 to a part of the support layer 170 through the first deforming layer 190 and the lower electrode 180, and the first upper electrode 200. The first upper electrode connecting member 230 is formed from one side of the first through the first insulating layer 220 and the support layer 170 to the common electrode line 240. The first upper electrode connecting member 230 connects the first upper electrode 200 and the common electrode line 240, and the first insulating layer 220 has the first upper electrode 200 and the lower electrode 180 mutually connected to each other. Connected to prevent electrical shorts. In addition, a second insulating layer 221 is formed from one side of the second upper electrode 201 to a part of the support layer 170 through the second deformable layer 191 and the lower electrode 180. The second upper electrode connecting member 231 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 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, and the second insulating layer 221 has the second upper electrode 201 and the lower electrode 180 mutually connected to each other. Connection to prevent electrical shorts.

A mirror 260 and a mirror 260 are formed in a portion of the lower electrode 280 where the first and second upper electrodes 200 and 201 are not formed, that is, a portion formed parallel to the support line 174. The post 250 supporting the lower hard mask 320 is formed. The mirror 260 and the hard mask 320 are centrally supported by the post 250, and both sides thereof are formed horizontally on the actuator 210 via the second air gap 310. The mirror 260 reflects light incident from a light source (not shown) at a predetermined angle so that the image is projected onto the screen.

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 accompanying drawings.

7A to 11B are diagrams for describing a method of manufacturing the apparatus shown in FIGS. 5 and 6. 7A to 11B, each a diagram is a manufacturing process diagram of the apparatus shown in FIG. 5, and each b diagram is a manufacturing process diagram of the apparatus illustrated in FIG. 6.

7A and 7B, after preparing a substrate 101 which is an n-type doped silicon wafer, an active region and a field region are formed on the substrate 101 using a silicon partial oxidation method (LOCOS), which is a conventional device isolation process. A device isolation film 125 is formed to distinguish between them. 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 by using an ion implantation process. M × N (M and N are natural numbers) P-MOS transistors 120 are formed on the substrate 101.

Subsequently, after the insulating film 130 made of oxide is formed on the substrate 101 on which the P-MOS transistor 120 is formed, the source 110 and the drain 105 are formed on the insulating film 130 by a photolithography method. Openings exposing the upper portion of each side of each). Subsequently, after depositing the first metal layer 135 made of titanium, titanium nitride, tungsten, nitride, or the like on the insulating layer 130 on which the openings are formed, 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 the bottom of the first anchor 171 formed later.

The first passivation layer 140 made of an insulator glass (PSG) is formed on the first metal layer 135 and the substrate 101. The first passivation layer 140 is formed to have a thickness of about 8000 Å using chemical vapor deposition (CVD). The first protective layer 140 prevents damage to the substrate 101 in which the transistor 120 is embedded due to a subsequent process.

The second metal layer 145 is formed on the first protective layer 140. The second metal layer 145 is formed by sputtering titanium to form a titanium layer having a thickness of about 300 mm 3, and then forming titanium nitride layer by forming titanium nitride on the titanium layer by physical vapor deposition (PVD). do. Since the light incident from the light source is incident not only on the mirror 260 but also on a portion other than the portion covered by the mirror 260, the second metal layer 145 may cause photocurrent to flow to the substrate 101, causing the device to malfunction. prevent. 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 to form a hole in the second metal layer 145. 147 is formed.

The second passivation layer 150 made of an insulated glass PSG is stacked on the second metal layer 145. The second protective layer 150 is formed to have a thickness of about 2000 kPa using a chemical vapor deposition method. The second protective layer 150 prevents the substrate 101 and the resulting products formed on the substrate 101 from being damaged during subsequent processing.

An etch stop layer 155 is stacked on the second passivation layer 150. The etch stop layer 155 prevents the second passivation layer 150 and the results on the substrate 101 from being etched during the subsequent etching process. The etch stop layer 155 is made of low temperature oxide (LTO) such as silicon oxide or phosphorus pentoxide. The etch stop layer 155 is laminated to have a thickness of about 0.2 to 0.8 μm at a temperature of about 350 to 450 ° C. by low pressure chemical vapor deposition (LPCVD).

The first sacrificial layer 160 is stacked on the etch stop layer 155. The first sacrificial layer 160 serves to facilitate stacking of the thin films constituting the actuator 210. The first sacrificial layer 160 is formed at a temperature of about 500 ° C. or less using polysilicon. The first sacrificial layer 160 is laminated to have a thickness of about 2.0 to 3.0 μm by low pressure chemical vapor deposition (LPCVD). 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 the first photoresist 163 on the first sacrificial layer 160, the first photoresist 163 is used as a mask, and then, below the first sacrificial layer 160. A portion of the second metal layer 145 having the hole 147 formed thereon and portions adjacent to both sides thereof are etched in a quadrangular shape to expose a portion of the etch stop layer 155, thereby supporting the supporting layer 170 formed later. The position where the anchor 171 and the second anchors 172a and 172b are to be formed is made. Thus, the etch stop layer 155 is exposed in the shape of three squares spaced apart by a predetermined distance. Next, the first photoresist 163 is removed.

8A and 8B, the first layer 169 is stacked on the upper portion of the etch stop layer 155 and the first sacrificial layer 160 exposed in a quadrangle as described above. The first layer 169 is made of a hard material such as nitride or metal, and is formed to have a thickness of about 0.1 to 1.0 μm by low pressure chemical vapor deposition (LPCVD). Subsequently, after the second photoresist 177 is coated and patterned on the first layer 169 using a photolithography method, the first sacrificial layer 160 is formed using the second photoresist 177 as a mask. A portion of the first layer 169 formed on the upper portion of the first layer 169 is etched to a predetermined depth to form a plurality of grooves in the first layer 169, and then the second photoresist 173 is removed. The plurality of grooves are formed in the two arms of the support layer 170 when the first layer 169 is later patterned with the support element 175, when the square ring shaped support layer 170 is later formed. When the grooves are formed in the first layer 169, the first layer 169 has a rib-shaped cross section as shown in FIG. 8B.

9A and 9B, the lower electrode layer 179 is stacked on top of the first layer 169 in which the plurality of grooves are formed as described above. The lower electrode layer 179 is made of a metal having electrical conductivity such as platinum, tantalum or platinum-tantalum, and is formed to have a thickness of about 0.1 μm to about 1.0 μm using a sputtering method or a chemical vapor deposition method. Since the lower electrode layer 179 is stacked on the first layer 169 having a plurality of grooves, a plurality of grooves having the same shape as the grooves of the first layer 169 are formed in the lower electrode layer 179. The lower electrode layer 179 is later applied with a first signal (image signal) from outside, and patterned as a mirror-shaped 'c' shaped lower electrode 180 having stepped protrusions corresponding to each other on one side.

A second layer 189 made of a piezoelectric material such as PZT or PLZT is formed on the lower electrode layer 179. Preferably, the second layer 189 is formed to have a thickness of about 0.4 μm by spin coating PZT prepared by the sol-gel method. Subsequently, the piezoelectric material constituting the second layer 189 is subjected to heat treatment by rapid thermal treatment (RTA) to cause phase shift. Since the second layer 189 is stacked on the first layer 169 and the lower electrode layer 179 having a plurality of grooves, a plurality of grooves are also formed in the second layer 189, as shown in FIG. 9B. And a cross-sectional lip shape of the second layer 189. The second layer 189 may be the first strained layer 190 and the second upper electrode 201, which are deformed by a first electric field generated between the first upper electrode 200 and one side of the lower electrode 180. And a second deformation layer 191 causing deformation by a second electric field generated between the other side of the lower electrode 180 and the other side.

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

10A and 10B, after applying and patterning a third photoresist (not shown) on the upper electrode layer 199, each of the upper electrode layers 199 may be squared using the third photoresist as a mask. After patterning the first upper electrode 200 and the second upper electrode 201 having a shape of a flat plate, preferably a rectangular flat plate and being spaced apart from each other by a predetermined distance, and then removing the second photoresist. do. The second signal is applied to the first and second upper electrodes 200 and 201 through the common electrode line 240 formed later from the outside, respectively.

Subsequently, the second deforming layer 190 is patterned in the same manner as the method of patterning the upper electrode layer 199, each having a shape of a rectangular flat plate, and separated from each other by a predetermined distance to form the first strained layer 190. And a second strained layer 191. In this case, the first and second deformable layers 190 and 191 are patterned to have a rectangular flat plate with a slightly larger area than the first and second upper electrodes 200 and 201, respectively.

Subsequently, the lower electrode layer 179 is patterned to have a mirror-shaped 'c' shape with respect to the support line 174 formed later, and has protrusions formed in a step shape toward the first anchor 171 at both sides of one side. The lower electrode 180 is formed. In this case, the two arms of the mirror-shaped 'c'-shaped lower electrode 180 have a rectangular flat plate having a larger area than the first and second deformable layers 190 and 191, respectively.

In addition, when the lower electrode layer 179 is patterned, the common electrode line 240 is formed simultaneously with the lower electrode 180 in a direction perpendicular to the lower electrode 180 on one side of the first layer 169. The common electrode line 240 is formed to be spaced apart from the lower electrode 180 by a predetermined distance on the support line 174 formed later. Accordingly, the first and second upper electrodes 200 and 201, the first and second strained layers 190 and 191, and the lower electrode 180 may be formed, and a plurality of grooves may be formed to have a structure strong against strain stress. An actuator 210 having a lip structure 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 and 172b. . At this time, of the portions of the first layer 169 that are in contact with the etch stop layer 155 exposed in the shape of the three quadrangles, both sides are the second anchors 172a and 172b, respectively, and the center portion is the first anchor ( 171). Each of the first anchor 171 and the second anchors 172a and 172b has a rectangular box shape, and a hole 147 of the second metal layer 145 and a first metal layer 145 are disposed below the first anchor 171. 135) the drain pad. The first and second deformable layers 190 and 191 are formed parallel to each other on two arms horizontally extending in a direction orthogonal to the support line 174 of the support layer 170, respectively. Accordingly, the first anchor 171 is formed below the mirror-shaped 'c' shaped lower electrode 180, and the second anchors 172a and 172b are formed below the outer electrode 180, respectively. .

Subsequently, a fourth photoresist (not shown) is applied and patterned on the support element 175 and the actuator 210 to form the first and second upper electrodes from the common electrode line 240 formed on the support line 274. Expose portions of 200 and 201. At this time, the protrusions of the lower electrode 180 are also exposed together from the first anchor 171.

Subsequently, by depositing and patterning a low temperature oxide such as amorphous silicon or silicon oxide to phosphorus pentoxide on the exposed portion, the first strained layer 190 and the lower electrode 180 are removed from a portion of the first upper electrode 200. The first insulating layer 220 is formed to a part of the support layer 170, and at the same time, a part of the support layer 170 is formed from the part of the second upper electrode 201 through the second strained layer 191 and the lower electrode 180. Until the second insulating layer 221 is formed. The first and second insulating layers 220 and 221 are formed to have a thickness of about 0.2 to 0.4 μm, respectively, by low pressure chemical vapor deposition (LPCVD).

Next, the first anchor 171 and the etch stop layer (from the center 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, a portion of the second passivation layer 150 and the first passivation layer 140 are etched to form a via hole 270 up to the drain pad of the first metal layer 135, and then the via hole 270 from the drain pad. Through vias 280 are formed to the protrusions of the lower electrode 180. At the same time, the first upper electrode connecting member 230 is formed from 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, and the second upper electrode The second upper electrode connecting member 231 is formed from the 201 to the common electrode line 240 through a portion of the second insulating layer 221 and the support layer 170.

The via contact 280 and the first and second upper electrode connecting members 230 and 231 are each made of a metal such as platinum, tantalum or platinum-tantalum, and each is about 0.1 to 0.2 μm by sputtering or chemical vapor deposition. After depositing to have a thickness of about the thickness is formed by patterning the deposited metal. The first and second upper electrode connecting members 230 and 231 connect the first and second upper electrodes 200 and 201 and the common electrode line 240, respectively, and the lower electrode 180 connects the via contact 280. It is connected to the drain pad of the first metal layer 135 through.

Referring to FIGS. 11A and 11B, sufficient to completely cover the actuator 210 using a spin coating method of acuflo having excellent deposition flatness on top of the actuator 210 and the support element 175. A second sacrificial layer 300 having a height is formed.

Subsequently, after the fifth photoresist 330 is coated on the second sacrificial layer 300, aluminum is sputtered on the second sacrificial layer 300 to form a hard mask 320 having a thickness of about 3000 μm. Subsequently, after the hard mask 320 is patterned by a photolithography method, the fifth photoresist 330 and the second sacrificial layer 300 are formed by using the patterned hard mask 320 as an etching mask. By patterning, a portion of the lower electrode 180 having a mirror-shaped 'c' shape formed parallel to the support line 174 (the first and second upper electrodes 200 and 201 are not formed thereon). Unexposed parts).

Next, aluminum (Al), which is the same metal as the hard mask 320, is deposited on a portion of the exposed lower electrode 180 and on the patterned hard mask 320 by using a sputtering method or a chemical vapor deposition method. The deposited aluminum is patterned to simultaneously form a mirror 260 having a rectangular flat plate shape and a post 250 supporting the mirror 260.

Subsequently, the second sacrificial layer 300 and the fifth photoresist 330 are removed by a plasma ashing method, and the first sacrificial layer 160 is formed using xenon fluoride (XeF ₂ ) or bromine fluoride (BrF ₂ ). ), And cleaning and drying treatments are performed to complete the AMA device as shown in FIGS. 4 to 6. As such, 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.

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 and the via contact 280 of the first metal layer 135. Is applied to the lower electrode 180, and at the same time, a second signal is applied to the first and second upper electrodes 200 and 201 through the common electrode line 240 from the outside, respectively, and thus, the first upper electrode 200 is applied. And a first electric field is generated between the one side of the lower electrode 180 and the second electric field according to the potential difference between the second upper electrode 201 and the other side of the lower electrode 180. The first deformation layer 190 formed between one side of the first upper electrode 200 and the lower electrode 180 causes deformation by the first electric field, and at the same time, the second upper electrode 201 is caused by the second electric field. And the second strained layer 191 formed between the other side of the lower electrode 180 cause deformation.

As the first and second deformable layers 190 and 191 contract in a direction orthogonal to the first and second electric fields, respectively, the actuator 210 including the first and second deformable layers 190 and 191 is predetermined. Bend at the angle of. The mirror 260 reflecting light incident from the light source is inclined together with the actuator 210 because the mirror 260 is supported by the post 250 and is formed on the actuator 210. 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 thin film type optical path control apparatus according to the present invention and a method of manufacturing the same, after forming a plurality of grooves by etching two arms extending horizontally in a direction orthogonal to the support line of the rectangular ring-shaped support layer to a predetermined depth, The lower electrode, the first and second strained layers, and the first and second upper electrodes are formed thereon. Since the lower electrode, the first and second strained layers, and the first and second upper electrodes are stacked on the support layer on which the plurality of grooves are formed, a plurality of grooves are formed along the shape of the support layer. Accordingly, the actuator including the lower electrode, the first and second strained layers and the first and second upper electrodes, each of which has a plurality of grooves, has a rib-shaped structure that is strong in strain stress. Therefore, it is possible to prevent the initial bending of the actuator, which is a phenomenon in which the actuator is bent upward or downward even without a driving voltage due to deformation stress such as residual stress generated during the formation of the actuator.

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

Claims (5)

An active matrix (100) having a MOS transistor (120) embedded therein and including a first metal layer (135) having a drain pad extending from the drain (105) of the transistor (120); Iii) a support line 174 formed on an upper portion of the active matrix 100, ii) a rectangular ring shape and integrally formed with the support line 174 and horizontally perpendicular to the support line 174. A support layer 170 having a plurality of grooves formed in two extending arms, and iii) each of the support layers 170 in contact with the active matrix 100 below the portion adjacent to the support line 174 of the support layer 170. Supporting means (175) including a first anchor (171) and second anchors (172a, 172b) for supporting the; It is formed on the support layer 170 and includes a lower electrode 180, the first strained layer 190, the second strained layer 191, the first upper electrode 200 and the second upper electrode 201. Actuator 210; A common electrode line 240 formed on the support line 174; And Thin film type optical path control device, characterized in that it comprises a mirror (260) formed on top of the actuator (210). The lower electrode 180 has a mirror-shaped 'c' shape with respect to the support line 174, and the first deformable layer 190 has a mirror-shaped 'c' shaped lower electrode. Is formed on the upper side of one of the two arms of 180, the first upper electrode 200 is formed on the first strained layer 190, the second strained layer 191 is the lower electrode The thin film type optical path control device, characterized in that formed on the upper side of the other of the two arms of the 180, the second upper electrode (201) is formed on the second deformation layer (191). 3. The method of claim 2, wherein two arms of the lower electrode 180, the first strained layer 190, the second strained layer 191, the first upper electrode 200, and the second upper electrode ( Thin film type optical path control device, characterized in that a plurality of grooves are formed in each of the support layer 170 in the 201). 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 a first sacrificial layer on the active matrix, and then patterning the first sacrificial layer to expose portions of the active matrix where both the drain pads are formed and both sides of the drain pads; Forming a first layer on the exposed active matrix and the first sacrificial layer, and then etching a portion of the first layer to form a plurality of grooves in the first layer; Forming a lower electrode layer, a second layer, and an upper electrode layer on the first layer in which the plurality of grooves are formed; Patterning the upper electrode layer, the second layer and the lower electrode layer to form an actuator including a first upper electrode, a second upper electrode, first and second strained layers, and a lower electrode; Patterning the first layer to form a support line formed on the active matrix, a support layer formed integrally with the support line to have a rectangular ring shape, and the plurality of grooves formed at both sides thereof, and adjacent to the support line among the support layers. Forming supporting means including first and second anchors respectively in contact with the active matrix under the portion; Forming a common electrode line on the support line; And Method of manufacturing a thin film type optical path control device comprising the step of forming a mirror on top of the actuator. The method of claim 4, wherein the forming of the plurality of grooves in the first layer is performed by photolithography to expose both sides of the first layer in a direction orthogonal to a direction in which the drain pad extends in the first layer. And etching the exposed portion to form a plurality of grooves.