KR20000044210A - Manufacturing method for thin film micromirror array-actuated device - Google Patents

Abstract

PURPOSE: A manufacturing method of the TMA device is provided to form a safe mirror by preventing the mirror from falling off the post when removing the second sacrificial layer by forming a safe post. 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 patterning and forming the first sacrificial layer on the upper part of the active matrix; a step of forming the supporting instrument including a supporting line, a supporting layer, a lower electrode layer, a second layer and an upper electrode layer; a step of forming a post hole by patterning and forming the second sacrificial layer using the multi-coating method; and a step of forming the supportive sub-part of the post at the side of the post hole.

Description

Manufacturing method of thin film type optical path control device

The present invention relates to a method for manufacturing a thin film type optical path control device using thin-film micromirror array-actuated (TMA), and more particularly, to a thin film type optical path that can improve the stability of a mirror by preventing a phenomenon in which a post and a mirror are separated. It relates to a manufacturing method of the adjusting device.

Optical path control devices or spatial light modulators for projecting optical energy onto the screen can 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 type image display device is a CRT (Cathode Ray Tube), which is called a CRT device, which has excellent image quality but increases its weight and volume as the size of the screen increases, leading to an increase in manufacturing cost. there is a problem. Examples of the projection image display apparatus include a liquid crystal display (LCD), a deformable mirror device (DMD), and an actuated mirror array (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 its inside is easy to overheat. In addition, the maximum light efficiency of existing transmission optical modulators is limited to a 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.

Such AMA devices are classified into bulk type and thin film type (TMA). The bulk optical path control device is disclosed in US Pat. No. 5,085,497 to Gregory U. et al. The bulk optical path control device is made by thinly cutting a multilayer ceramic to mount a ceramic wafer having a metal electrode formed therein into an active matrix in which transistors are built, and then processing it using a sawing method and installing a mirror thereon. 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 (TMA) that can be manufactured using a semiconductor manufacturing process has been developed. Such a thin film type optical path control device is disclosed in Korean Patent Application No. 98 -..... .

The manufacturing method of the thin film type optical path control device described in the preceding application is as follows.

Figure 1 shows a perspective view of the thin film type optical path control device described in the preceding application, Figure 2 shows a cross-sectional view of the device of Figure 1 cut along the line A ₁ -A ₂ , Figures 3a to 3c is shown in Figure 2 Figures for explaining the manufacturing method of the device shown.

Referring to FIG. 3A, an isolation layer 6 for dividing an active region and a field region is formed on a substrate 1, which is an n-type silicon wafer, and a gate 4 made of polysilicon is formed on the active region. After that, by forming the p ⁺ source 3 and the drain 2 in the ion implantation process, M x N (M and N are natural numbers) P-MOS transistors 5 are formed on the substrate 1.

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 the one side of the source 3 and the drain 2 by photolithography. Next, after depositing the first metal layer 8 made of titanium, titanium nitride, tungsten, nitride, or the like on the resultant, the first metal layer 8 is patterned. The first metal layer 8 includes a drain pad extending from the drain 2 of the transistor 5 to the bottom of the first anchor 21.

A first passivation layer 9 is formed on the first metal layer 8 and the substrate 1 to prevent damage to the substrate 1 in which the transistor 5 is embedded. The first protective layer 9 is formed to have a thickness of 8000 kPa by depositing silicate glass (PSG) by chemical vapor deposition (CVD). 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 having a thickness of 300 μs, and then depositing titanium nitride on the top by physical vapor deposition (PVD) to form a titanium nitride layer having a thickness of 1200 μs. do. The second metal layer 10 prevents the device from malfunctioning due to the light leakage current caused by the incident light flowing to the substrate 1. Subsequently, a portion of the second metal layer 10 in which the via hole 38 is formed later, that is, a portion in which the drain pad of the first metal layer 8 is positioned is etched to etch a hole in the second metal layer 10 (not shown). Not formed).

The second protective layer 12 is formed on the second metal layer 10 by depositing silicate glass PSG by chemical vapor deposition. The active matrix 16 is completed by stacking the etch stop layer 13 on the second passivation layer 12 to prevent the second passivation layer 12 and the resultant on the substrate 1 from being etched during the subsequent etching process. do. The etch stop layer 13 is formed of a low temperature oxide such as silicon oxide (SiO ₂ ) or phosphorus pentoxide (P ₂ O ₅ ), and is formed to have a thickness of 0.2 to 0.8 μm by low pressure chemical vapor deposition (LPCVD).

The first sacrificial layer 14 is stacked on the etch stop layer 13. The first sacrificial layer 14 is formed to have a thickness of 2.0 to 3.0 μm by depositing polysilicon 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 metal layer 10 below the first sacrificial layer 14 is used as a mask. The first anchor 21 and the second anchors 22a and 22b supporting the supporting layer 19 formed later by etching the portion where the hole of the hole and the portions adjacent to both sides thereof are etched to expose a portion of the etch stop layer 13. ) And the first photoresist is removed. Accordingly, the etch stop layer 13 is exposed in three rectangular shapes (not shown) spaced apart by a predetermined distance.

The first layer 17 is stacked on the upper portion of the etch stop layer 13 and the first sacrificial layer 14 exposed in a rectangular shape as described above. The first layer 17 is formed by depositing nitride by a low pressure chemical vapor deposition method to have a thickness of 0.1 ~ 1.0㎛. The lower electrode layer 23 formed by the sputtering method or the chemical vapor deposition method is stacked on the first layer 17. The lower electrode layer 23 is made of metal such as platinum (Pt), tantalum (Ta), or platinum-tantalum (Pt-Ta), and has a thickness of 0.1 to 1.0 mu m. 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 to have a thickness of 0.1 to 1.0 mu m by depositing platinum, tantalum, silver, or platinum-tantalum by a sputtering method or a chemical vapor deposition method.

Referring to FIG. 3B, after coating and patterning a second photoresist (not shown) on the upper electrode layer 28, the upper electrode layer 28 is patterned using the mask as shown in FIG. 1. Each of the first and second upper electrodes 29 and 30 having the shape of a rectangular flat plate and spaced apart by a predetermined distance is formed, and then the second photoresist is removed.

Subsequently, the second layer 25 is patterned in the same manner as the patterning of the upper electrode layer 28, so that the first and second deformed layers 26 and 27, each having a rectangular flat plate shape and spaced apart by a predetermined distance, are formed. Form. 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 addition, when the lower electrode layer 23 is patterned, a common electrode line 32 is formed simultaneously with 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.

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 which contacts the etch stop layer 13 exposed in the three rectangular shapes are second anchors 22a and 22b, and the central portion of the first layer 17 is the first anchor 21. Becomes Each of the first anchor 21 and the second anchors 22a and 2b has a rectangular box shape, the first anchor 21 is formed below the lower electrode 24, and the second anchors 22a are formed. , 22b are formed on the outer bottom of the lower electrode 24, respectively.

Subsequently, a third photoresist (not shown) is applied on top of the support element 18 and the actuator 31 and patterned to form the first and the first from the common electrode line 32 formed on the support line 19. 2 A part of the upper 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 part 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 up to a part of the support layer 19, and at the same time, a part of the support layer 19 is formed from the part of the second upper electrode 30 through the second strained layer 27 and the lower electrode 24. 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 µm, respectively, by a low pressure chemical vapor deposition method.

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, from the first upper electrode connecting member 36 and the second upper electrode 30 to the common electrode line 32 from the first upper electrode 29 to the upper part of the first insulating layer 34 and the support layer 19. The second upper electrode connecting member 37 is formed through the upper portions of 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, the second sacrificial layer 42 is formed by multi-coating a photoresist on top of the actuator 31 and the support element 18.

Subsequently, the second sacrificial layer 42 is patterned to form the mirror 41 and the post 40, so that the second sacrificial layer 42 is not adjacent to the support line 20 of the 'C' lower electrodes 24. A portion of the formed portion (that is, the portion where the first and second upper electrodes 29 and 30 are not formed) is exposed to form a post hole. Next, a metal such as aluminum (Al) having a reflective property is deposited on the post hole and the second sacrificial layer 42 by sputtering or chemical vapor deposition. Then, the deposited metal is patterned to form a rectangular flat plate. A mirror 41 having a shape and a post 40 supporting the mirror 41 are simultaneously formed. After etching the second sacrificial layer 42, the first sacrificial layer 14 is removed with xenon fluoride (XeF ₂ ) or bromine fluoride (BrF ₂ ), and the cleaning and drying treatment is performed in FIG. 1. The TMA element as shown is completed.

However, in the above-described manufacturing method of the thin film type optical path control device, when the second coating is formed by forming a second sacrificial layer by multi-coating the photoresist, when patterning it to form a post, when the first coating of the second sacrificial layer There is a problem that the weak portion occurs in the connection portion between the photoresist and the second coated photoresist, after which the mirror and the post is separated from each other when the second sacrificial layer is removed. This will be described with reference to the drawings.

4 is an enlarged view of a portion 'B' of FIG. 3C. Referring to FIG. 4, after the photoresist is multi-coated on the actuator 31 and the support element 18 to form the second sacrificial layer 42, the second sacrificial layer 42 is etched to form a post hole. In forming, the connection portion of the primary coated photoresist and the secondary coated photoresist is excessively etched (over-etched) so that the weak portion C is connected to the connection portion of the primary coated photoresist and the secondary coated photoresist. Occurs. When the metal is deposited to form the mirror 41 and the post 40 in the state where the fragile portion C is generated as described above, the thickness of the metal deposited on the fragile portion C of the post hole is greater than that of the mirror 41. ) And extremely thin compared to the periphery of the weak part. Therefore, when the second sacrificial layer 40 and the fourth photoresist 44 are removed, a problem arises in which the upper mirror 41 of the weak portion C is separated from the post 40.

Accordingly, it is an object of the present invention to provide a method of manufacturing a thin film type optical path control device that can prevent the mirror from being detached from the post to improve the stability of the mirror.

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. 2.

4 is an enlarged cross-sectional view of a portion 'B' of FIG. 3C.

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

FIG. 6 is a cross-sectional view of the apparatus of FIG. 5 taken along line D ₁ -D _2. FIG.

7A to 7F are manufacturing process diagrams of the apparatus shown in FIG. 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 255: post reinforcement member

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 method of manufacturing a thin film type optical path control device comprising the step of providing an active matrix, forming an actuator, forming a support element, and forming a mirror To provide. The active matrix includes a MOS transistor, and a first metal layer having a drain pad extending from the drain of the transistor is formed. The actuator and the support element are formed by sequentially forming a first layer, a lower electrode layer, a second layer and an upper electrode layer on the active matrix, and then patterning the upper electrode layer sequentially. The actuator includes a first and a second upper electrode, a first and a second deformable layer, and a lower electrode, and the support element includes a support layer, a support line, and a first anchor and a second anchor formed by patterning the first layer. It includes. The forming of the mirror may include forming a second sacrificial layer on the actuator and the support means, patterning the second sacrificial layer to form a post hole, and then spin the upper part of the post hole and the second sacrificial layer. A silicon oxide film is formed by using an on glass method, and the silicon oxide film is patterned to form a post reinforcing member on the side of the post hole, and then aluminum is deposited on the upper and post holes of the second sacrificial layer.

According to the present invention, after forming the post hole by patterning the second sacrificial layer, the post reinforcing member is formed on the side of the post hole, thereby preventing the mirror from being detached from the post when the second sacrificial layer is removed. Can be formed.

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

Figure 5 shows a perspective view of the thin film type optical path control apparatus according to the present invention, Figure 6 shows a cross-sectional view of the device of Figure 5 cut by the line D ₁ -D ₂ .

5 and 6, the thin film type optical path control apparatus according to the present invention, the active matrix 100, the support element 175 formed on the active matrix 100, the actuator formed on the support element 175 210, and a mirror 260 formed on the actuator 210.

The active matrix 100 includes a substrate 101 having M × N (M, N is a natural number) P-MOS transistors 120, a drain 105 and a source 110 of the P-MOS transistors 120. 2) formed on the first metal layer 135 formed on the substrate 101, the first passivation layer 140 formed on the first metal layer 135, and the first passivation layer 140 formed on the substrate 101. The metal layer 145, 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.

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.

Referring to FIG. 5, the support element 175 includes a support line 174, a support layer 170, 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 along a direction orthogonal to the support line 174 on the same plane. A first anchor 171 is integrally formed with the two arms and etched in a lower portion between two arms horizontally extending in a direction orthogonal to the support line 174 of the support layer 170 having the shape of a square ring. Attached to the barrier layer 155, two second anchors 172a and 172b are 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 each have a shape of a rectangular box.

The support layer 170 is centrally supported by the first anchor 171 and both sides are supported by the second anchors 172a and 172b, so that the cross-sections of the support layer 170 and the anchors 171, 172a and 172b As shown in FIG. 5, it has a 'T' shape.

The first anchor 171 is formed at a portion of the etch stop layer 155 where the drain pad of the first metal layer 135 is located. In the central portion of the first anchor 171, the first metal layer may be formed through the etch stop layer 155, the second passivation layer 150, the holes (not shown) of the second metal layer 145, and the first passivation layer 140. The via hole 270 is formed to the drain pad of the 135.

The actuator 210 has a mirror-shaped 'c' shape with respect to the support line 240 and is formed on the support layer 170. 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 inside 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 to the protrusions of the lower electrode 180 through the via hole 280 to electrically connect the drain pad and the lower electrode 180.

The two arms of the lower electrode 180 each have a shape of a rectangular plate, and the first and second deformable layers 190 and 191 respectively have a shape of a rectangular plate having a smaller area than the two arms of the lower electrode 180. And is formed on top of two arms of the lower electrode 180. In addition, the first and second upper electrodes 200 and 201 have a shape of a rectangular plate having a smaller area than the first and second deformable layers 190 and 191, respectively, and have the first and second deformed layers 190 and 191. It is formed at the top of the.

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 to each other, and the first insulating layer 220 may include the first upper electrode 200 and the lower electrode 180. They are connected to each other 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 after passing through 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.

Posts for supporting mirrors in portions of the mirror-shaped 'C'-shaped lower electrode 180 where the first and second upper electrodes 200 and 201 are not formed, that is, parallel to the support line 174. 250 is formed. A post reinforcing member 255 is formed outside the post 250 to surround the post 250. The mirror 260 is supported at the center portion by the post 250, and both sides thereof are horizontally formed on the upper portion of the actuator 210 via the second air gap 310. The mirror 260 performs a function of reflecting 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 accompanying drawings.

7A to 7F are diagrams for describing a method of manufacturing the apparatus shown in FIGS. 5 and 6. In Figs. 7A to 7F, the same reference numerals are used for the same members as Figs. 5 and 6.

Referring to FIG. 7A, after preparing a substrate 101 made of an n-type silicon wafer, the substrate 101 may be divided into an active region and a field region by using a silicon partial oxidation (LOCOS) method, which is a conventional device isolation process. The device isolation layer 125 is formed. 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 x N (M and N are natural numbers) P-MOS transistors 120 are formed.

After forming an insulating layer made of oxide on the resultant formed P-MOS transistor 120, by using a photolithography method to form openings for exposing the top of one side of the source 110 and the drain 105, respectively. Subsequently, after depositing the first metal layer 135 made of titanium, titanium nitride, tungsten, nitride, or the like on the resultant, 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.

A first passivation layer 140 made of insulated glass (PSG) is formed on the first metal layer 135 and the substrate 101. The first protective layer 140 is formed to have a thickness of about 8000 kPa by chemical vapor deposition (CVD). The first protective layer 140 prevents damage to the substrate 101 in which the 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 is formed by sputtering titanium to form a titanium layer having a thickness of about 300 ms, and then depositing titanium nitride on the top thereof by physical vapor deposition (PVD) to form a titanium nitride layer having a thickness of about 1200 ms. It is completed by forming a. Since the light incident from the light source is incident not only to the mirror 260 but also to a portion other than the portion covered by the mirror 260, the light leakage current flows through the active matrix 100, causing the device to malfunction. To prevent it. 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 positioned is etched to be etched to form a hole in the second metal layer 145. Not shown).

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 by chemical vapor deposition. 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 results on the second passivation layer 150 and the substrate 101 from being etched during the subsequent etching process. The etch stop layer 155 is made of a low temperature oxide such as silicon oxide or phosphorus pentoxide. 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. Therefore, the active matrix 100 including the substrate 101, the first metal layer 135, the first protective layer 140, the second metal layer 145, the second protective layer 150, and the etch stop layer 155. Is completed.

The first sacrificial layer 160 made of polysilicon 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 to have a thickness of about 2.0 to 3.0 μm by a low pressure chemical vapor deposition 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.

7B is a plan view illustrating a state in which the first sacrificial layer 160 is patterned. 6A and 7B, after applying and patterning a first photoresist (not shown) on the first sacrificial layer 160 and using the mask as a mask, the lower part of the first sacrificial layer 160 may be used. The first anchor 171 and the second anchors 172a and 172b are formed later by etching the portion where the hole of the second metal layer 145 and the portions adjacent to both sides thereof are etched to expose a portion of the etch stop layer 155. Create a location to be. 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. 7C, the first layer 169 is stacked on the etch stop layer 155 and the first sacrificial layer 160 exposed in a quadrangle as described above. The first layer 169 is formed by depositing a hard material such as nitride by low pressure chemical vapor deposition to have a thickness of about 0.1 to 1.0 μm. The first layer 169 is later patterned with a support element 175.

The lower electrode layer 179 is stacked on top of the first layer 179. The lower electrode layer 179 is formed to have a thickness of about 0.1 to 1.0 μm by depositing a metal having electrical conductivity such as platinum, tantalum or platinum-tantalum by a sputtering method or a chemical vapor deposition method. The lower electrode layer 179 is later applied with a first signal (image signal) from the outside and patterned into a lower electrode 180 having a mirror-shaped 'c' shape.

A second layer 189 made of a piezoelectric material such as PZT or PLZT is stacked on the lower electrode layer 179. 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 heat treatment by a rapid thermal treatment (RTA) method for phase shifting. The second layer 189 may be the first strained layer 190 and the second upper electrode 210 which are deformed by a first electric field generated between the first upper electrode 200 and the lower electrode 180 later. 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 formed by depositing a metal having electrical conductivity such as platinum, tantalum, silver, or platinum-tantalum by sputtering or chemical vapor deposition to have a thickness of about 0.1 to 1.0 μm. 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.

Referring to FIG. 7D, after applying and patterning a second photoresist (not shown) on the upper electrode layer 199, the upper electrode layer 199 may be squared using the second photoresist as a mask. The first upper electrode 200 and the second upper electrode 201 have a shape of a flat plate, preferably a rectangular flat plate, and are spaced apart from each other by a predetermined distance. 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 photoresist is removed.

Subsequently, the second strain layer 189 is patterned in the same manner as the patterning of the upper electrode layer 199 to have a rectangular flat plate, and the first strained layer 190 spaced apart from each other by a predetermined distance. The second strained layer 191 is formed. In this case, as shown in FIG. 4, the first and second deformable layers 190 and 191 are patterned to have a rectangular flat plate shape slightly wider than the first and second upper electrodes 200 and 201, respectively.

Subsequently, the lower electrode layer 179 is patterned in the same manner as the patterning of the upper electrode layer 199 to have a mirror-shaped 'C' shape for the support line 174 formed later, and the first anchor 171 may be formed. Towards the lower electrode 180 having a protrusion formed in a stepped shape is formed. In this case, the two arms of the lower electrode 180 have the shape of a rectangular flat plate having a larger area than the first and second deforming 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. Thus, the actuator 210 including the first and second upper electrodes 200 and 201, the first and second strained layers 190 and 191, and the lower electrode 180 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, both sides of the portion of the first layer 169 which contacts the etch stop layer 155 exposed in the three quadrangles are second anchors 172a and 172b, and the center portion of the first anchor 171 is do. 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 and a hole of the first metal layer 135 are disposed below the first anchor 171. The drain pad is located.

The first and second upper electrodes 200 and 201 are formed parallel to each other on two arms horizontally extending in a direction perpendicular to the support line 174 of the support layer 170, respectively. Accordingly, the first anchor 171 is formed below the lower electrode 180, and the second anchors 172a and 172b are formed below the outer electrode 180, respectively.

Subsequently, a third photoresist (not shown) is applied on top of the support element 175 and on the actuator 210 and patterned to form a first upper portion from the common electrode line 240 formed on the support line 174. Up to a portion of the electrode 200 and the second upper electrode 201 are exposed. At this time, the protrusions of the lower electrode 180 are also exposed together from the first anchor 171.

Subsequently, the first strained layer 190 and the lower electrode 180 may be removed from a part of the first upper electrode 200 by depositing and patterning amorphous silicon or silicon oxide or phosphorus pentoxide, which is a low temperature oxide, on the exposed portion. The first insulating layer 220 is formed up to a part of the support layer 170, and at the same time, the support layer 170 is formed through the second strained layer 191 and the lower electrode 180 from a part of the second upper electrode 201. The second insulating layer 221 is formed to a part. 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, preferably about 0.3 μm, respectively, using a low pressure chemical vapor deposition method.

The first anchor 171, the etch stop layer 155, and the second anchor 171 are formed from the center of the first anchor 171, which is a portion where the hole of the second metal layer 145 and the drain pad of the first metal layer 135 are positioned. After etching the passivation layer 150 and the first passivation layer 140 to form the via hole 270 to the drain pad, the via contact 280 from the drain pad to the protrusions of the lower electrode 180 through the via hole 270. ). At the same time, the first upper electrode connecting member 230 and the second upper electrode 201 extend from the first upper electrode 200 to the common electrode line 240 after passing over the first insulating layer 220 and the support layer 170. The second upper electrode connecting member 231 is formed from the upper portion of the second insulating layer 221 and the support layer 170 to the common electrode line 240.

The via contact 280 and the first and second upper electrode connection members 230 and 231 are deposited to have a thickness of about 0.1 to 0.2 μm by depositing platinum or platinum-tantalum by sputtering or chemical vapor deposition. This deposited metal is then patterned to form. 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 through.

Referring to FIG. 7E, the second sacrificial layer 300 is formed by multi-coating AccuLop on top of the actuator 210 and the support element 175. Subsequently, the second sacrificial layer is patterned so that a portion of the lower '180'-shaped lower electrode 180 which is not adjacent to the support line 174 and formed in parallel (ie, the first and second upper electrodes thereon). (200, 201) portion is not formed) to form a post hole.

In addition, a silicon oxide (SiO ₂ ) film is formed on the second sacrificial layer 300 by using a spin on glass (SOG) method.

Referring to FIG. 7F, the silicon oxide film formed as described above is patterned to form a post reinforcing member on the side of the post hole.

As described above, when the post reinforcing member is formed on the side of the post hole by using the spin-on glass method, when the second sacrificial layer is patterned to form the post hole, the fragile portion generated by overetching between the multi-coated acculo is formed. The post reinforcing member may be reinforced, and then the mirror and the post may be stably connected when the mirror and the post are formed, thereby preventing the mirror from being detached from the post when the second sacrificial layer is removed.

Subsequently, aluminum, which is a reflective metal on the top and post holes of the second sacrificial layer, is deposited by sputtering or chemical vapor deposition to form mirrors and posts.

Subsequently, the second sacrificial layer 300 is removed using an oxygen plasma (O ₂ plasma), and then the first sacrificial layer 160 is removed with xenon fluoride (XeF ₂ ) or bromine fluoride (BrF ₂ ) and cleaned. And drying treatment to complete the TMA element as shown in FIG. 4. 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.

According to the present invention, after forming the post hole by patterning the second sacrificial layer, a silicon oxide film is formed on the second sacrificial layer and the post hole by using a spin on glass method, and then patterned to form a post hole on the side of the post hole. By forming a reinforcing member and forming a mirror and a post on top of the second sacrificial layer and the post hole, it is caused by the over-etching of the connection portion between the multi-coated acculo during the patterning process of the second sacrificial layer for forming the post hole. Since the weak reinforcing part may be reinforced with a post reinforcing member to form a stable post, the mirror may be prevented from being removed from the post when the second sacrificial layer is removed to form a stable mirror.

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

Claims (2)

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 on the active matrix; Forming a first layer, a lower electrode layer, a second layer, and an upper electrode layer on the first sacrificial layer; Patterning the upper electrode layer, the second layer and the lower electrode layer to form an actuator including a lower electrode, a first strained layer, a second strained layer, a first upper electrode, and a second upper electrode; Patterning the first layer to form a support line, a support layer, and support means including first and second anchors; Forming a second hole by applying an acculator to the actuator and the support means by a multi-coating method to form a second sacrificial layer; Forming a post reinforcing member on the side of the post hole; And And forming a mirror on top of the post reinforcement member and the second sacrificial layer. The method of claim 1, wherein the forming of the post reinforcing member comprises forming a silicon oxide film on the second sacrificial layer and the post hole by using a spin on glass method, and then patterning the silicon oxide film. Method of manufacturing a thin film type optical path control device, characterized in that performed.