KR20000044181A - Manufacturing method for thin film micromirror array-actuated device - Google Patents

Abstract

PURPOSE: A manufacturing method for the device is provided to minimize the occurrence of the point default at a pixel by preventing the electric short from happening between the first upper electrode and the first lower electrode and between the second upper electrode and the lower electrode. CONSTITUTION: A device comprises an active matrix(100), a transistor(120), a first metal layer(135), a second protection layer(140), a second metal layer(145), a second protection layer(150), an etching preventing layer(155), a supporting layer(170), a first anchor(171), and a supporting line(174). A method comprises the steps of providing the active matrix having a drain pad which is extended from the drain of the transistor and which has MOS transistor inside; and forming the first layer on the sacrificial layer after patterning and forming the sacrificial layer on the upper part of the active matrix. The method further comprises the step of forming the second actuating part including the second lower electrode and the first actuating part including the first lower electrode using the photo-resist as a mask.

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 apparatus using thin-film micromirror array-actuated (TMA), and more specifically, to blankets residues generated during the formation of the first and second actuators. After etching, the present invention relates to a method of manufacturing a thin film type optical path control apparatus capable of minimizing point defects of a pixel by forming a first insulating layer and a second insulating layer.

Optical path control devices or spatial light modulators for projecting optical energy onto a screen may be applied to various fields such as optical communication, image processing, and information display devices. The image processing apparatus using the optical path control device or the spatial light modulator typically has a direct view 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). The CRT device is called a CRT, which has excellent image quality but increases in weight and volume as the screen is enlarged, leading to an increase in manufacturing cost. There is. Projection-type image display devices include a liquid crystal display (LCD), a deformable mirror device (DMD), and an AMA. Such projection image display devices can be further divided into two groups according to their optical characteristics. That is, devices such as LCDs can be classified as transmissive spatial light modulators, while DMD and AMA can be classified as reflective spatial light modulators.

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

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

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

These AMA devices are largely divided into bulk type and thin film type. The bulk optical path control device is disclosed in US Pat. No. 5,085,497 to Gregory Um et al. The bulk optical path control device is made by thinly cutting a multilayer ceramic to mount a ceramic wafer having a metal electrode therein into an active matrix in which a transistor is built, and then processing it using a sawing method and installing a mirror on the top. . 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. The thin film type optical path control device is disclosed in Korean Patent Application No. 96-59191 (name of the invention: thin film type optical path control device which can improve the light efficiency), which is filed by the applicant of the Korean Patent Office on November 28, 1996.

1 is a plan view of the thin film type optical path control device described in the preceding application, FIG. 2 is a perspective view of the device of FIG. 1, and FIG. 3 is a cross-sectional view of the device of FIG. _{2 taken along} line A ₁ -A _2. It is shown. 1 to 3, the thin film type optical path control device includes an active matrix 1 and an actuator 65 and a mirror 60 formed on the active matrix 1.

The active matrix 1 in which M x N (M and N are integers) containing MOS transistors (not shown) includes a drain pad 5, an active matrix 1, and a drain pad extending from the drain of the MOS transistor. A protective layer 10 stacked on top of (5) and an etch stop layer 15 stacked on top of the protective layer (10).

The actuator 65 may be anchors 31a and 31b supporting both sides of the lower portion of one side of the etch stop layer 15 at which the drain pad 5 is formed and supporting the actuator 65. Membrane 30, the lower electrode 35 stacked on top of membrane 30, the strained layer 40 stacked on top of lower electrode 35, and the other side of the membrane 30 formed horizontally through the air gap 25, The upper electrode 45 stacked on the layer 40 and the strained layer 130, the lower electrode 35, the membrane 30, the etch stop layer 15, and the protective layer 10 from one side of the strained layer 40. The via contact 55 includes a via contact 55 formed to connect the lower electrode 35 and the drain pad 5 to the inside of the via hole 50 perpendicular to the drain pad 5.

Referring to FIG. 2, the membrane 30 has a rectangular flat plate formed integrally with the arms on the same plane between two rectangular arms formed in parallel from both sides of the anchor 31. It has a shape. The mirror 60 is formed on the rectangular flat plate of the membrane 30. Thus, the mirror 60 has the shape of a rectangular flat plate.

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

4A to 4D show a manufacturing process diagram of the thin film type optical path control device. Referring to FIG. 4A, a protective layer 10 is formed on top of an active matrix 1 having M × N MOS transistors (not shown) formed therein and a drain pad 5 extending from a drain of the MOS transistor. Laminated. The protective layer 10 is formed of phosphorus silicate glass (PSG) to have a thickness of about 1.0 to 2.0 μm using chemical vapor deposition (CVD). The protective layer 110 prevents damage to the active matrix 1 in which the MOS transistor is embedded during the subsequent process.

An etch stop layer 15 is stacked on the passivation layer 10. The etch stop layer 15 is formed to have a thickness of about 1000 to 2000 kPa using a low pressure chemical vapor deposition (LPCVD) method. The etch stop layer 15 prevents the active matrix 1 and the protective layer 10 having the transistor embedded therein from being etched due to a subsequent etching process.

The sacrificial layer 20 is stacked on the etch stop layer 15. The sacrificial layer 20 is formed of the silicate glass to have a thickness of about 0.5 to 4.0 μm by atmospheric chemical vapor deposition (APCVD). In this case, since the sacrificial layer 20 covers the top of the active matrix 1 in which the MOS transistors are embedded, the surface flatness is very poor. Accordingly, the surface of the sacrificial layer 20 is planarized by using spin on glass (SOG) or chemical mechanical polishing (CMP). Subsequently, a portion of the sacrificial layer 20 having a drain pad 5 formed thereon and an adjacent portion thereof are etched to expose a portion of the etch stop layer 15 so as to expose anchors 31a that are the supporting portions of the actuator 65. 31b) is formed.

Referring to FIG. 4B, the membrane 30 is stacked on the exposed etch stop layer 15 and the sacrificial layer 20. The membrane 30 is formed to have a thickness of about 0.1 to 1.0 ㎛ using a low pressure chemical vapor deposition method. Subsequently, a lower electrode 35 is stacked on top of the membrane 30 using a metal such as platinum, tantalum or platinum-tantalum. The lower electrode 35 is formed to have a thickness of about 0.1 to 1.0 μm by using a sputtering method, and then the lower electrode 35 is formed to have an Iso − in order to apply an independent first signal for each pixel. cutting. The first signal (image signal) is externally applied to the lower electrode 35 through the MOS transistor and the drain pad 5 embedded in the active matrix 1.

The strained layer 40 is stacked on the lower electrode 35. Deformation layer 40 is a piezoelectric material such as PZT or PLZT using a sol-gel method, sputtering method or chemical vapor deposition (CVD) method of 0.1 to 1.0㎛, preferably, about 0.4㎛ It is formed to have a thickness. Subsequently, the piezoelectric material constituting the strained layer 40 is phase shifted by using a rapid heat treatment (RTA) method.

The upper electrode 45 is stacked on top of the strained layer 40. The upper electrode 45 is formed to have a thickness of about 0.1 to 1.0 μm using aluminum, platinum, or silver by sputtering. The second electrode (bias signal) is applied to the upper electrode 45 through a common electrode line (not shown) from the outside. Therefore, when the first signal is applied to the lower electrode 35 and the second signal is applied to the upper electrode 45, an electric field is generated according to the potential difference between the upper electrode 45 and the lower electrode 35. According to the electric field, the deformation layer 40 formed between the upper electrode 45 and the lower electrode 35 causes deformation.

Referring to FIG. 4C, after applying and patterning a first photoresist layer (not shown) on the upper electrode 45 by spin coating, the first photoresist layer is used as a mask. As a result, the upper electrode 45 is patterned to have a mirror-shaped 'c' shape. Subsequently, after removing the first photoresist layer, a second photoresist layer (not shown) is applied and patterned on top of the patterned upper electrode 45 and the deformable layer 40, and then patterned. Using the second photoresist layer as a mask, the strained layer 40 is patterned to have a mirror-shaped 'c' shape slightly wider than the upper electrode 45. Subsequently, after removing the second photoresist layer, a third photoresist layer (not shown) is applied on the upper electrode 45, the deforming layer 40, and the lower electrode 35 by spin coating. After patterning, the lower electrode 35 is patterned to have a mirror-shaped 'c' shape slightly wider than the deformation layer 40 using the third photoresist layer as a mask.

Subsequently, the strained layer 40, the lower electrode 35, the membrane 30, the etch stop layer 15, and the protective layer 10 are removed from the portion of the strained layer 40 in which the drain pad 5 is formed below. After etching to form a via hole 50 from one side of the strained layer 40 to the drain pad 5, a method of sputtering a metal such as tungsten (W), platinum, aluminum or titanium in the via hole 50 is performed. The via contact 55 is formed so that the drain pad 5 and the lower electrode 35 are connected to each other. Therefore, the first signal is applied from the outside to the lower electrode 35 through the MOS transistor, the drain pad 5, and the via contact 55 embedded in the active matrix 1. Thereafter, the third photoresist layer is removed.

Referring to FIG. 4D, after the fourth photoresist layer (not shown) is coated and patterned on the lower electrode 35 and the via hole 50, the fourth photoresist is patterned as described above. The membrane 30 is patterned using the layer as a mask. In this case, the membrane 30 extends from the anchors 31a and 31b, which are both supporting portions, has a rectangular shape slightly wider than the lower electrode 35, and the central portion of the membrane 30 integrally formed therewith has a rectangular shape. Is patterned into a flat plate. That is, as shown in FIG. 2, the membrane 30 has rectangular arms formed from the anchors 31a and 31b, which are both support portions, and a rectangular flat plate having a larger area than the arms is formed in the same plane between the arms. It has a shape formed integrally with the arms on the. Subsequently, the fourth photoresist layer is removed. As a result of the patterning of the membrane 30 as described above, a portion of the sacrificial layer 20 is exposed.

Subsequently, a fifth photoresist layer (not shown) is applied on the exposed sacrificial layer 20 and the membrane 30 by spin coating, followed by patterning the fifth photoresist layer to form the membrane. The rectangular flat plate 30 of the center portion 30 is exposed. Subsequently, after sputtering a metal such as silver, platinum, or aluminum to a thickness of about 0.3 to 2.0 μm on the upper portion of the membrane 30 exposed in the rectangular shape, the sputtered metal is exposed to the rectangular exposed membrane. Patterned to have the same shape as the shape of 30 to form a mirror (60). After the fifth photoresist layer and the sacrificial layer 20 are removed using hydrogen fluoride (HF) vapor, the active matrix 1 on which the actuator 65 is formed is rinsed and dried. Is performed to form M × N TMA elements.

However, according to the manufacturing method of the above-described thin film type optical path control device, during the formation of the actuator using an etching method using a photoresist, an etching residue or a photoresist residue remains on the sidewall between the upper electrode and the lower electrode. The upper electrode and the lower electrode are connected to each other through the residue, thereby causing an electrical short between the upper electrode and the lower electrode. When an electrical short occurs between the upper electrode and the lower electrode, the corresponding actuator is not driven, which eventually causes a point defect of the pixel.

Accordingly, an object of the present invention is to remove the etch residue and photoresist residue generated during the formation of the first and second actuators by blanket etching, and then use the low temperature oxide to remove the first insulating layer and the first The present invention provides a method of manufacturing a thin film type optical path control apparatus capable of minimizing point defects of a pixel by preventing an electrical short between an upper electrode and a lower electrode by forming an insulating layer.

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

FIG. 2 is a perspective view of the apparatus shown in FIG. 1. FIG.

3 is a cross-sectional view taken along line A ₁ -A ₂ of the apparatus of FIG.

4A to 4D are manufacturing process diagrams of the apparatus shown in FIG. 3.

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

6 is a perspective view of the apparatus shown in FIG. 5.

FIG. 7 is a cross-sectional view of the apparatus shown in FIG. 6 taken along line B ₁ -B ₂ .

8A to 8E are manufacturing process diagrams of the apparatus shown in FIG.

<Explanation of symbols for the main parts of the drawings>

100: active matrix 120: transistor

135: first metal layer 140: first protective layer

145: second metal layer 150: second protective layer

155: etch stop layer 160: first sacrificial layer

170: support layer 171: first anchor

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

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

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

210, 211: first and second actuating parts

220, 221: first and second insulating layers

230 and 231: first and second upper electrode connecting members

250: Post 260: Mirror

270: Beer Hall 280: Beer Contact

290 and 291: first and second lower electrode connection members

300: second sacrificial layer

In order to achieve the above object of the present invention, the present invention provides an active matrix including a first metal layer having a drain pad in which a MOS transistor is embedded and extending from the drain of the transistor, and having a first on top of the active matrix. A first actuator and a second upper electrode, a second deformed layer, and a second lower electrode including a first upper electrode, a first deformed layer, and a first lower electrode are formed on the first layer. After forming a second actuating part including a patterning the first layer, the support means formed on the active matrix, the support layer formed integrally with the support line, and the support means including the first and second anchors Forming the first actuating part and the second actuating part, and removing the etch residue and the photoresist residue by blanket etching. A first insulating layer is formed from one side of the first upper electrode in the portion adjacent to the branch line to a part of the support layer through the first strained layer and the first lower electrode, and from one side of the second upper electrode in the portion adjacent to the support line. After forming the second insulating layer to a part of the support layer through the first strained layer and the second lower electrode, a thin film type optical path control device comprising the step of forming a mirror on top of the first actuating portion and the second actuating portion It provides a method for producing. The first insulating layer and the second insulating layer are formed to have a thickness of about 500 GPa or more using silicon dioxide (SiO ₂ ) or phosphorus pentoxide (P ₂ O ₅ ) using a plasma enhanced chemical vapor deposition (PECVD) method.

According to the present invention, after forming the first actuating part and the second actuating part, an etching residue or a photoresist residue generated during the formation of the first and second actuating parts is blanket-etched. The first insulating layer and the second insulating layer are respectively formed on the upper side of one side of the first actuating part and the second actuating part. Accordingly, the first upper electrode, the first lower electrode, the second upper electrode, and the second lower electrode are connected to each other so that an electrical short occurs between the first upper electrode, the first lower electrode, the second upper electrode, and the second lower electrode. It is possible to prevent the occurrence of point defects of the pixel by preventing it.

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.

5 is a plan view showing a thin film type optical path control device according to the present invention, Figure 6 shows an enlarged perspective view of the actuator and the mirror of the device of Figure 5, Figure 7 is a B ₁ B ₂ of the device of FIG. The cross-sectional view is shown in a line.

5 and 6, the thin film type optical path control apparatus according to the present invention is formed side by side on the active matrix 100, the support element 175 formed on the active matrix 100, the top of the support element 175 The first actuating part 210 and the second actuating part 211 and a mirror 260 formed on the first actuating part 210 and the second actuating part 211 are included.

Referring to FIG. 7, the active matrix 100 having M × N (M, N is an integer) P-MOS transistors 120 includes a drain 105 and a source of the P-MOS transistor 120. A first metal layer 135 formed on top of the active matrix 100, a first passivation layer 140 formed on the first metal layer 135, and a first passivation layer 140 formed on the active matrix 100. The second metal layer 145, the second passivation layer 150 formed on the second metal layer 145, and the etch stop layer 155 formed on the second passivation layer 150 are included. The first metal layer 135 includes a drain pad extending from the drain 105 of the P-MOS transistor 120 to the bottom of the first anchor 171 to transmit a first signal (image signal). The second metal layer 145 includes a titanium (Ti) layer and a titanium nitride (TiN) layer, and an opening 147 is formed in a portion of the second metal layer 145 in which the drain pad is formed.

6-7, 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 active matrix 100 via the first air gap 165. A common electrode line 240 is formed on a portion of 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, integrally with the support line 174 on one side of the support line 174 along a direction perpendicular to the support plane 174 in the same plane orthogonal to the support line 174. Is formed. A first anchor 171 is integrally formed with the two arms in a lower portion between two arms horizontally extending in a direction orthogonal to the support line 174 of the support layer 170 having a rectangular ring shape. It is attached to the etch stop layer 155, and two second anchors 172a and 172b are formed integrally with the two arms and attached to the etch stop layer 155 at the lower outer side of the two arms.

The first anchor 171 and the second anchors 172a and 172b respectively supporting the support layer 170 are formed under a portion of the support layer 170 adjacent to the support line 174 so that the etch stop layer 155 is formed. Is attached to. The first anchor 171 and the second anchors 172a and 172b each have a rectangular box shape. The support layer 170 and the support line 174 are horizontally formed on the etch stop layer 155 via the first air gap 165. 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. 7, the shape has a 'T' shape. The support layer 170 performs a function of a membrane supporting the actuator of the thin film type optical path control device described in the previous application.

The first anchor 171 is formed on a portion in which the drain pad of the first metal layer 135 is formed below the etch stop layer 155. The first metal layer 135 is formed in the central portion of the first anchor 171 through the etch stop layer 155, the second passivation layer 150, the opening 147 of the second metal layer 145, and the first passivation layer 140. The via hole 270 is formed up to the drain pad of the via hole, and the via contact 280 is formed inside the via hole 270.

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

The first lower electrode 180 is stacked in the shape of a square flat plate having a protrusion formed on one side of the two arms of the support layer 170. Preferably, the first lower electrode 180 has a 'L' shape on the mirror and is spaced apart from the support line 174 by a predetermined distance. The protrusion of the first lower electrode 180 is formed on one side of the first anchor 171 and extends to a portion adjacent to the via hole 270.

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

The second lower electrode 181 is stacked in the shape of a square plate having a protrusion formed on one side of the two arms of the support layer 170 on the other side, corresponding to the first lower electrode 180. Preferably, the second lower electrode 181 is formed in parallel with the first lower electrode 180 in a shape of 'L' on a mirror and is spaced apart from the support line 174 by a predetermined distance. The protrusion of the second lower electrode 181 is formed on the other side of the first anchor 171 and extends to a portion adjacent to the via hole 270. Therefore, the protrusion of the first lower electrode 180 and the protrusion of the second lower electrode 181 are spaced apart from each other by a predetermined distance with respect to the via hole 270.

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

A first lower electrode connecting member 290 is formed from the via contact formed in the via hole 270 in the center of the first anchor 171 to the protrusion of the first lower electrode 180, and the second contact from the via contact is formed. The second lower electrode connecting member 291 is formed to the protrusion of the lower electrode 181. Accordingly, the drain pad of the first metal layer 135 and the first lower electrode 180 are connected to each other through the via contact and the first lower electrode connecting member 290, and the second lower electrode 181 is connected to the via contact and the first lower electrode 180. 2 is connected to the drain pad of the first metal layer 135 through the lower electrode connecting member 291.

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

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

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

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

8A to 8E are diagrams for describing a method of manufacturing the apparatus shown in FIG. 7. 8A to 8E, the same reference numerals are used for the same members as in FIG.

Referring to FIG. 8A, after an active matrix 100 made of silicon doped with n-type is prepared, an active region may be formed in the active matrix 100 using silicon partial oxidation (LOCOS), which is a conventional device isolation process. An isolation layer 125 is formed to distinguish the active region and the field region. Subsequently, after forming the gate 115 made of a conductive material such as polycrystalline silicon doped with impurities on the active region, the p ⁺ source 110 and the drain 105 are formed by using an ion implantation process. M × N (M, where N is an integer) P-MOS transistors 120 are formed in the active matrix 100.

After the insulating film 130 made of oxide is formed on the P-MOS transistor 120 is formed, the opening for exposing the top of one side of the source 110 and the drain 105, respectively, using a photolithography method. Form them. Subsequently, the first metal layer 135 made of titanium, titanium nitride, tungsten, nitride, or the like is deposited on the resultant formed product, and then the first metal layer 135 is patterned by photolithography. The patterned first metal layer 135 includes a drain pad extending from the drain 105 of the P-MOS transistor 120 to a lower portion of the first anchor 171 supporting the support layer 170.

The first passivation layer 140 is formed on the first metal layer 135 and the active matrix 100. The first passivation layer 140 is formed of phosphoric silicate (PSG), and has a thickness of about 8000 kPa using chemical vapor deposition (CVD). The first protective layer 140 prevents damage to the active matrix 100 in which the P-MOS 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 forms a titanium layer having a thickness of about 300 kW using a sputtering method of titanium, and then uses a titanium vapor phase physical vapor deposition (PVD) method on the titanium layer to about 1200 kW. It is completed by forming a titanium nitride layer having a thickness. Since the light incident from the light source is incident on the second metal layer 145 not only the mirror 260 but also a portion other than the portion covered by the mirror 260, photocurrent flows through the active matrix 100, causing the device to malfunction. To prevent them. Subsequently, a portion of the second metal layer 145 in which the via hole 270 is to be formed in a subsequent process, that is, a portion in which the drain pad of the first metal layer 135 is formed is etched to form a hole in the second metal layer 145. By forming (not shown), the via contact (not shown) formed later and the second metal layer 145 are not contacted.

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

An etch stop layer 155 is stacked on the second passivation layer 150. The etch stop layer 155 prevents the second passivation layer 150 and the results on the active matrix 100 from being etched due to a subsequent etching process. The etch stop layer 155 is made of low temperature oxide (LTO) such as silicon oxide (SiO ₂ ) or phosphorus pentoxide (P ₂ O ₅ ). The etch stop layer 155 is formed to have a thickness of about 0.2 to 0.8 μm at a temperature of about 350 to 450 ° C. using a low pressure chemical vapor deposition (LPCVD) method.

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

Subsequently, after applying and patterning a first photoresist (not shown) on top of the first sacrificial layer 160, the lower part of the first sacrificial layer 160 is used as the etching mask. The first anchor 171 and the first supporting part 177 which are formed later by exposing a portion of the etch stop layer 155 by etching the part where the hole of the second metal layer 145 is formed and parts adjacent to both sides thereof are exposed. The two anchors 172a and 172b are made to be formed. Thus, the etch stop layer 155 is exposed in the shape of three squares spaced apart by a predetermined distance.

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

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

A second layer 189 made of a piezoelectric material such as PZT or PLZT is stacked on the lower electrode layer 179. The second layer 189 is formed to have a thickness of about 0.1 μm to 1.0 μm using the sol-gel method, the sputtering method, or the chemical vapor deposition method. Preferably, the second layer 189 is formed to have a thickness of about 0.4 μm by sputtering PZT prepared by the sol-gel method. Subsequently, the piezoelectric material constituting the second layer 189 is subjected to heat treatment by a rapid heat treatment method to cause phase shift. The second layer 189 may be the first strained layer 190 and the second upper electrode 201 that are deformed by a first electric field generated between the first upper electrode 200 and the first lower electrode portion 180. ) Is patterned into a second strained layer 191 causing strain by a second electric field generated between the second lower electrode portion 181.

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

Referring to FIG. 8C, after applying and patterning a second photoresist layer (not shown) on the upper electrode layer 199, the upper electrode layer 199 is used using the second photoresist layer as a mask. Each of the substrates is patterned into a first upper electrode 200 and a second upper electrode 201 which have a rectangular flat plate shape, preferably a rectangular flat plate plate, and are separated from each other by a predetermined distance (see FIG. 6). . A second signal is applied to the first upper electrode 201 and the second upper electrode 201 through a common electrode line 240 formed later from the outside, respectively. Subsequently, the second photoresist layer is removed.

Subsequently, the second layer 189 is patterned in the same manner as the method of patterning the upper electrode layer 199 into the first upper electrode 200 and the second upper electrode 201 to form a rectangular flat plate. The first strained layer 190 and the second strained layer 191 are formed to be separated from each other by a predetermined distance and formed side by side. In this case, as shown in FIG. 6, the first strained layer 190 and the second strained layer 191 have a rectangular plate shape slightly wider than the first upper electrode 200 and the second upper electrode 201, respectively. It is patterned to have.

Subsequently, the lower electrode layer 179 is patterned in the same manner as the patterning of the upper electrode layer 199 to form the first lower electrode 180 and the second lower electrode 181. The first lower electrode 180 has a shape of a square plate having a protrusion formed at one side thereof, that is, a 'L' shape on the mirror, and the second lower electrode 181 has a protrusion formed at one side corresponding to the first lower electrode 180. It has the shape of the rectangular plate formed, that is, the shape of the 'L'. In addition, when the lower electrode layer 179 is patterned, the common electrode line 240 is disposed on the upper side of the first layer 169 in a direction orthogonal to the first lower electrode 180 and the second lower electrode 181. It is formed simultaneously with the first lower electrode 180 and the second lower electrode 181.

Each of the first lower electrode 180 and the second lower electrode 181 has a slightly larger area than the first strained layer 190 and the second strained layer 191, and the common electrode line 240 is formed later. A portion of the first lower electrode 180 and the second lower electrode 181 is spaced apart from the first lower electrode 180 by a predetermined distance. Accordingly, the first actuating part 210 including the first upper electrode 200, the first strained layer 190, and the first lower electrode 180, the second upper electrode 201, and the second strained layer ( The second actuating part 211 including the 191 and the second lower electrode 181 is completed.

Subsequently, the first layer 169 is patterned to form a support element 175 comprising a support layer 170, a support line 174, a first anchor 171 and second anchors 172a and 172b. . At this time, both sides of the portion of the first layer 169 that contacts the etch stop layer 155 exposed in the shape of the three quadrangles become second anchors 172a and 172b, and the center portion of 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 of the second metal layer 145 is formed under the first anchor 171.

The support layer 170 has a rectangular annular shape, preferably a rectangular annular shape, and is integrally formed with the supporting line 174. In this state, when the first sacrificial layer 160 is removed later, a supporting element 175 having a shape as shown in FIG. 6 is formed. That is, the support layer 170 has a shape of a rectangular ring and is integrally formed with the support line 174 on one side of the support line 174 along a direction perpendicular to the support plane 174 in the same plane orthogonal to that of the rectangular ring. A first anchor 171 is integrally formed with the two arms in the lower portion between the two arms horizontally extending in a direction orthogonal to the support line 174 of the supporting layer 170 having a shape, thereby preventing the etch stop layer 155. The second anchors 172a and 172b may be integrally formed with the arms, respectively, and attached to the etch stop layer 155 at the outer lower portion of the two arms. The first anchor 171 and the second anchors 172a and 172b which together support the support layer 170 are formed at a lower portion of the support layer 170 adjacent to the support line 174.

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

Referring to FIG. 8D, the first actuating part 210 and the first actuating part 210 and the first resist part 210 to remove the etching residue and the photoresist residue generated during the formation of the first actuating part 210 and the second actuating part 211 are formed. The blanket is etched from the side of the second actuator 211, that is, from the first upper electrode 200 to the first lower electrode 180 and from the second upper electrode 201 to the second lower electrode 181.

Subsequently, a third photoresist layer may be disposed on the support element 175 including the support layer 170 and the support line 174, and on the first actuating part 210 and the second actuating part 211. (Not shown) and after patterning it, the first side of the first actuating part 210, the axis of the second actuating part 211, and the common electrode line 240 formed on the support line 174. The first upper electrode 200 and the second upper electrode 201 are exposed. At this time, the protrusion of the first lower electrode 180 and the protrusion of the second lower electrode 181 are also exposed together from the first anchor 171. Subsequently, silicon dioxide or phosphorus pentoxide (P ₂ O ₅ ), which is a low temperature oxide, is deposited on the exposed portion from the common electrode line 240 to the first upper electrode 200 and the second upper electrode 201 and patterned. As a result, the first insulating layer 220 is formed from a part of the first upper electrode 200 to a part of the support layer 170 through the first strained layer 190 and the first lower electrode 180, and at the same time, the second insulating layer 220 is formed. The second insulating layer 221 is formed from a portion of the upper electrode 201 to a portion of the support layer 170 through the second strained layer 191 and the second lower electrode 181. The first insulating layer 220 and the second insulating layer 221 are formed to have a thickness of about 500 kPa or more using a plasma enhanced chemical vapor deposition method. The first insulating layer 220 and the second insulating layer 221 are electrically connected between the first upper electrode 200 and the first lower electrode 180, and the second upper electrode 201 and the second lower electrode 181, respectively. In addition to preventing a short circuit, a function of protecting the first actuator 210 and the second actuator 211 is also performed during the subsequent etching process.

The first anchor 171, the etch stop layer 155, and the second protection from the center upper portion 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 formed below. After etching the layer 150 and the first protective layer 140 to form a via hole 270 to the drain pad, a via contact (not shown) is formed inside the via hole 270, and from the via contact The first lower electrode connecting member 290 and the second lower electrode connecting member 291 are formed to the protrusion of the first lower electrode 180 and the protrusion of the second lower electrode 181, respectively. 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 through a part of the first insulating layer 220 and the support layer 170. The second upper electrode connecting member 231 is formed from the second insulating layer 221 and the support layer 170 to the common electrode line 240.

The via contact, the first lower electrode connecting member 290, the second lower electrode connecting member 291, the first upper electrode connecting member 230, and the second upper electrode connecting member 231 are platinum or platinum-tantalum, respectively. After the deposition by using a sputtering method or a chemical vapor deposition method having a thickness of about 0.1 ~ 0.2㎛, and formed by patterning the deposited metal. The first upper electrode connecting member 230 and the second upper electrode connecting member 231 connect the first upper electrode 200, the second upper electrode 201, and the common electrode line 240, respectively. The first lower electrode 180 is connected to the drain pad of the first metal layer 135 through the first lower electrode connecting member 290 and the via contact, and the second lower electrode 181 is connected to the second lower electrode connecting member ( 291) and a via contact to the drain pad.

Referring to FIG. 8E, the first actuating part 210 is applied by spin coating a fourth photoresist on the first actuating part 210, the second actuating part 211, and the support element 175. ) And the second sacrificial layer 300 having a sufficient height to completely cover the second actuating part 211. Subsequently, by patterning the second sacrificial layer 300 to form the mirror 260 and the post 250, the second sacrificial layer 300 is formed to be parallel to the support line 174 of the support layer 170 having the shape of the square ring. Expose part of the part. Next, a metal such as aluminum (Al) having excellent reflectivity is deposited on a part of the exposed support layer 170 and on the second sacrificial layer 300 by using a sputtering method or a chemical vapor deposition method, and depositing the deposited metal. By patterning to form a mirror 260 having a shape of a square plate and a post 250 for supporting the mirror 260 at the same time.

Subsequently, the first sacrificial layer 160 and the second sacrificial layer 300 are removed using xenon fluoride (XeF ₂ ) or bromine fluoride (BrF ₂ ). 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. Then, the active matrix 100 formed with the first actuator 210 and the second actuator 211 is cleaned and dried to complete the TMA device as shown in FIG. 6.

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

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

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

As described above, according to the present invention, after forming the first actuating part and the second actuating part, the etching residue or the photoresist residue generated during the formation of the first actuating part and the second actuating part, etc. The blanket is etched and completely removed to form a first insulating layer and a second insulating layer from one side of the first and second upper electrodes adjacent to the supporting line to a part of the supporting layer. Accordingly, the first upper electrode, the first lower electrode, the second upper electrode, and the second lower electrode are connected to each other so that an electrical short circuit occurs between the first upper electrode, the first lower electrode, the second upper electrode, and the second lower electrode. It is possible to prevent the occurrence of point defects in the pixel by preventing it.

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

Claims (3)

Providing an active matrix with M × N (M, N is an integer) embedded therein and having a drain pad extending from the drain of the transistor; After forming and patterning a sacrificial layer on the active matrix, forming a first layer on the sacrificial layer; Applying a photoresist on top of the first layer and using the photoresist as a mask, the first actuating part including the first upper electrode, the first deformable layer and the first lower electrode, the second upper electrode, the second Forming a second actuator including a strained layer and a second lower electrode; Patterning the first layer to form support means formed on the active matrix, a support layer integrally formed with the support line, and first and second anchors; Blanket etching and removing the etch residue and the photoresist residue generated during the formation of the first and second actuating portions; A first insulating layer is formed from one side of the first upper electrode in the portion adjacent to the support line to a part of the support layer through the first strained layer and the first lower electrode, and one side of the second upper electrode in the portion adjacent to the support line. Forming a second insulating layer from a portion of the support layer through to the first strained layer and the second lower electrode; And And forming a mirror on top of the first actuating part and the second actuating part. The apparatus of claim 1, wherein the forming of the first insulating layer and the second insulating layer is performed using a plasma enhanced chemical vapor deposition (PECVD) method to have a thickness of about 500 GPa or more. Method of preparation. The method of claim 1, wherein the forming of the first insulating layer and the second insulating layer comprises silicon dioxide (SiO ₂ ) or hydrogen phosphide, which is a low-temperature oxide produced by reacting silane (SiH ₄ ) with oxygen (O ₂ ). A method of manufacturing a thin film type optical path control device, comprising phosphorus pentoxide (P ₂ O ₅ ), which is a low-temperature oxide produced by reacting PH ₃ ) with oxygen (0 ₂ ).