KR100251098B1 - Thin film actuated mirror array and manufacturing method of the same - Google Patents

Abstract

PURPOSE: A method for manufacturing a thin film type light path controlling apparatus is provided to prevent a lower electrode from being damaged and improve a reproduction of an etching process by making a thickness of a strain layer equal. CONSTITUTION: A drain pad(105) is formed on an active matrix(100). A protective layer(110) is formed on the drain pad(105) and the active matrix(100) to protect the active matrix(100) having a transistor. An etching preventing layer(115) is laminated on the protective layer(110). The first layer is laminated on the exposed etching preventing layer(115) and is patterned into a supporting layer(125). A lower electrode layer is formed on the first layer using a conductive metal and is patterned into a lower electrode(130) approving the first signal. The second layer is laminated on the lower electrode layer and is patterned into a strain layer(135). An upper electrode layer is laminated on the second layer and is patterned into an upper electrode with a specific pixel shape. A via hole(145) is formed with etching the strain layer(135), the lower electrode(130), the etching preventing layer(115) and the protective layer(110) from a side of the strain layer(135) to an upper part of the drain pad(105).

Description

Manufacturing method of thin film type optical path control device

The present invention relates to a method of manufacturing AMA (Actuated Mirror Arrays), which is a thin film type optical path control device. More specifically, the strained layer is patterned by a two-step process to uniformly vary the thickness of the strained layer at the support portion and other portions of the actuator. As a result, the present invention relates to a method of manufacturing a thin film type optical path control device, which facilitates the subsequent etching process and prevents damage to the lower electrode due to etching of the strained layer, thereby forming a stable actuator.

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 adjusting device or the spatial light modulator typically has a direct-view image display device and a projection-type image device according to a method of displaying optical energy on a screen. display device).

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, contrast can be improved to obtain a bright and clear image.

These AMA devices are largely divided into bulk type and thin film type. The bulk optical path control device is disclosed in US Pat. No. 5,085,497 to Gregory Um et al. The bulk optical path adjusting device is made by thinly cutting a multilayer ceramic to mount a ceramic wafer having a metal electrode formed therein in an active matrix in which a transistor is embedded, and then processing by a sawing method and installing a mirror thereon. However, the bulk optical path control device requires very high precision in design and manufacture, and has a disadvantage in that the response of the deformable part is slow.

Accordingly, a thin film type optical path control apparatus that can be manufactured using a semiconductor manufacturing process has been developed. The thin film type optical path control device is disclosed in the patent application No. 96-42197 (name of the invention: thin film type optical path control device that can control the stress of the membrane and a method of manufacturing the same) of the applicant filed on September 24, 1996 have.

FIG. 1 shows a plan view of the thin film type optical path adjusting device described in the above prior application, and FIG. 2 shows a cross-sectional view taken along the line AA ′ of the device shown in FIG. 1.

1 and 2, the thin film type optical path control device includes an active matrix 1 and an actuator 60. An active matrix 1 having M × N (M, N is an integer) MOS transistors and a drain pad 5 formed on one side thereof includes the active matrix 1 and A passivation layer 10 stacked on top of the drain pad 5 and an etch stop layer 15 stacked on top of the passivation layer 10 are included.

The actuator 60 is a membrane in which one side is in contact with a portion of the etch stop layer 15 in which the drain pad 5 is formed and the other side is parallel to the active matrix 1 via the air gap 25. 30, a lower electrode 35 stacked on the membrane 30, a strained layer 40 stacked on the lower electrode 35, and an upper electrode stacked on the strained layer 40. 45, a via hole vertically formed from one side of the strained layer 40 to the drain pad 5 through the lower electrode 35, the membrane 30, the etch stop layer 15, and the protective layer 10. The lower electrode 35 and the drain pad 5 are formed in the via contact 55 to be electrically connected to each other.

A stripe 46 is formed on a portion of the upper electrode 45. The stripe 46 operates the upper electrode 45 uniformly to prevent diffuse reflection of light incident from the light source.

Hereinafter, a method of manufacturing the thin film type optical path control device will be described with reference to FIGS. 3A to 3D.

Referring to FIG. 3A, a silicate glass (phosphor-) is formed on an active matrix 1 having M × N (M and N are integers) transistors (not shown) and a drain pad 5 formed on one side thereof. A protective layer 10 made of silicate glass (PSG) is formed. The protective layer 10 is formed to have a thickness of about 1.0 μm using chemical vapor deposition (CVD). The protective layer 10 protects the active matrix 1 from subsequent processes.

An etch stop layer 15 made of nitride is formed on the protective layer 10. The etch stop layer 15 may be formed to have a thickness of about 0.1 μm to about 1.0 μm using a low pressure chemical vapor deposition (LPCVD) method. The etch stop layer 15 prevents the protective layer 10 and the active matrix 1 from being etched during the subsequent etching process.

The sacrificial layer 20 is formed on the etch stop layer 15. The sacrificial layer 20 is formed of a PSG having a high concentration of phosphorus (P) to have a thickness of about 1.0 μm to 3.0 μm by using an atmospheric pressure chemical vapor deposition (APCVD) method. In this case, since the sacrificial layer 20 covers the upper portion of the active matrix 1 in which the transistor is 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 in which the drain pad 5 is formed is etched to expose a portion of the etch stop layer 15 to form a position where the support portion of the actuator is to be formed.

Referring to FIG. 3B, the membrane 30 is formed on the exposed etch stop layer 15 and the sacrificial layer 20 to a thickness of about 0.1 μm to about 1.0 μm. The membrane 30 forms nitride using low pressure chemical vapor deposition (LPCVD). At this time, by forming the membrane 30 while varying the ratio of the reaction gas in the reaction vessel of low pressure, the stress in the membrane 30 is controlled.

On the membrane 30, for example, a lower electrode 35 made of platinum (Pt) -tantalum (Ta) is formed. Subsequently, the lower electrode 35 is etched to short the lower electrode 35 for each pixel so that an independent first signal (image signal) is applied to each pixel (Iso 화소 Cut etching process).

The deformation layer 40 formed of PZT or PLZT is formed on the lower electrode 35. The strained layer 40 is formed to have a thickness of about 0.1 μm to about 1.0 μm, preferably about 0.4 μm using a sol-gel method, and then a phase change is performed by a rapid thermal annealing (RTA) method. Makes it. The deformation layer 40 is deformed by an electric field generated between the upper electrode 45 that is a common electrode and the lower electrode 35 that is a signal electrode.

The upper electrode 45 is formed on the strained layer 40. The upper electrode 45 is formed of a metal having excellent electrical conductivity and reflectivity such as aluminum or platinum so as to have a thickness of about 0.1 to 1.0 μm using a sputtering method. The second signal (bias signal) is applied to the upper electrode 45 which is the common electrode. In addition, the upper electrode 45 also functions as a mirror that reflects light incident from the light source.

Referring to FIG. 3C, the upper electrode 45 is patterned into a predetermined pixel shape. In this case, the stripe 46 is patterned so that the stripe 46 is formed on one side of the upper electrode 45. Subsequently, the strained layer 40 and the lower electrode 35 are sequentially patterned into a predetermined pixel shape, and then the strained layer 40 is formed from an upper portion of one side of the strained layer 40 to an upper portion of the drain pad 5. The via hole 50 is formed by sequentially etching the lower electrode 35, the membrane 30, the etch stop layer 15, and the protective layer 10. Subsequently, a metal such as tungsten, platinum or titanium is deposited by a lift-off method to form a via contact 55 that electrically connects the drain pad 5 and the lower electrode 35. Therefore, the via contact 55 is formed vertically from the lower electrode 35 to the top of the drain pad 5 in the via hole 50. Therefore, the first signal applied from the outside is applied to the lower electrode 35 through the transistor, the drain pad 5, and the via contact 55 embedded in the active matrix 1.

Referring to FIG. 3D, a photoresist layer (not shown) is coated on the entire surface of the resultant product in which the via contact 55 is formed and patterned to expose the membrane 30. Subsequently, the membrane 30 is anisotropically etched using the photoresist layer as an etching mask, thereby patterning a predetermined pixel shape. Subsequently, the air gap 25 is formed by isotropically etching the sacrificial layer 20 by 49% hydrogen fluoride (HF) vapor using the photoresist layer as an etching mask. Subsequently, the AMA device is completed by removing the photoresist layer and performing a cleaning and drying process to remove the remaining etching solution.

In the above-described thin film type optical path adjusting device, the first signal applied from the outside is applied to the lower electrode 35 through the MOS transistor, the drain pad 5, and the via contact 55 embedded in the active matrix 1. In addition, a second signal is applied to the upper electrode 45 from the outside through the common electrode line to generate an electric field between the upper electrode 45 and the lower electrode 35. By the electric field, the strained layer 40 stacked between the upper electrode 45 and the lower electrode 35 causes deformation. The strained layer 40 contracts in a direction perpendicular to the electric field, and the actuator 60 including the strained layer 40 is bent upward at a predetermined angle. Therefore, the upper electrode 45 on the actuator 60 is also inclined in the same direction. Light incident from the light source is reflected by the upper electrode 45 inclined at a predetermined angle and then projected onto a screen to form an image.

In the thin film type optical path adjusting device described in the above-mentioned prior application, the membrane is formed by using a chemical vapor deposition (CVD) method, and the lower electrode and the upper electrode are physical vapor deposition (PVD), such as a sputtering method. The step difference between the supporting part and the other part of the actuator is not significantly different since it is formed by the method. However, since the strained layer is formed using the sol-gel method, a large step is generated between the supporting portion of the actuator and the other portions. Therefore, when the stacked thin films are formed to form a pixel having a predetermined shape, in order to etch the deformed layer into a pixel shape, etching conditions must be precisely adjusted, thereby reducing reproducibility of the etching process. That is, since the thickness of the supporting portion of the actuator of the strained layer is thicker than the thickness of the other portion, when the strained layer is patterned, the other portion is excessively etched, thereby causing damage to the lower electrode formed under the strained layer. . As such, when the etching proceeds excessively and the lower electrode is damaged, the first signal applied from the outside is not evenly applied to the lower electrode, thereby preventing the deformation layer from causing deformation.

Accordingly, it is an object of the present invention to make the thickness of the strained layer uniform by first etching the supporting portion of the actuator when patterning the strained layer into a pixel shape, thereby facilitating control of subsequent etching processes, and etching the strained layer. The present invention provides a method of manufacturing a thin film type optical path control apparatus capable of preventing a lower electrode from being damaged and forming a stable actuator.

1 is a plan view of the membrane of the thin film type optical path control device previously applied by the applicant.

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

3A to 3D are manufacturing process diagrams of the apparatus shown in FIG. 2.

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

5 is an enlarged plan view of a portion 'B' of the apparatus of FIG. 4.

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

7A to 7D are manufacturing process diagrams of the apparatus shown in FIG. 4.

<Explanation of symbols for main parts of drawing>

100: active matrix 105: drain pad

110: protective layer 115: etching prevention layer

120: sacrificial layer 125: support layer

130: lower electrode 135: strained layer

140: upper electrode 145: empty hole

150: free contact 155: iso-cut

160: air gap 200: actuator

In order to achieve the above object, the present invention provides a step of providing an active matrix having a drain pad formed on one side and M x N (M, N is an integer), and an actuator formed on top of the active matrix It provides a method for manufacturing a thin film type optical path control apparatus comprising the step of. The forming of the actuator may include: (i) stacking a first layer such that one side is in contact with an upper portion of the active matrix and the other side is parallel to a lower portion of the active matrix; ii) a lower electrode layer is formed on the upper portion of the first layer. Laminating, iii) laminating a second layer on top of the lower electrode layer, iii) forming an upper electrode layer on top of the second layer, iii) patterning the upper electrode layer to form an upper electrode (Iii) forming a strained layer, comprising first patterning a portion of the second layer in contact with the active matrix, and second patterning the second layer, iii) the lower portion Patterning the electrode layer to form a lower electrode, and iii) patterning the first layer to form a support layer.

In the thin film type optical path adjusting device according to the present invention, the first signal applied from the outside is applied to the lower electrode through the transistor, the drain pad, and the via contact embedded in the active matrix. In addition, a second signal is applied to the upper electrode through the common electrode line from the outside to generate an electric field between the upper electrode and the lower electrode. Due to this electric field, the strain layer formed between the upper electrode and the lower electrode causes deformation. The strained layer contracts in a direction perpendicular to the generated electric field, and the actuator including the strained layer is bent at a predetermined angle. Therefore, the upper electrode on the actuator is also inclined in the same direction. Light incident from the light source is reflected by the upper electrode inclined at a predetermined angle as described above, and then is projected onto a screen to form an image.

Therefore, according to the manufacturing method of the thin film type optical path control apparatus according to the present invention, in order to reduce the step difference between the support portion of the actuator and the other portion of the deformable layer, the portion formed on the support portion of the actuator is first etched and then the remaining portion is formed into a pixel shape. By patterning, thickness of a strained layer can be made uniform in the support part part of an actuator, and other parts. Therefore, it is possible to prevent the lower electrode from being damaged by excessive etching due to the imbalance of the strain layer thickness. In addition, it is possible to easily control the etching depth and to increase the reproducibility of the etching process.

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

4 is a plan view of a support layer of the thin film type optical path control device according to the present invention, FIG. 5 is an enlarged plan view of a portion 'B' of the device shown in FIG. 4, and FIG. 6 is a CC ′ line of the device shown in FIG. 4. It shows a cross-sectional view cut into.

4 to 6, the thin film type optical path adjusting device according to the present invention includes an active matrix 100 having M × N MOS transistors (not shown) and an actuator 200 formed on the active matrix 100. ).

The active matrix 100 extends from the drain region of the transistor so that the drain pad 105, the drain pad 105, and the protection layer 110 formed on the active matrix 100 are formed on one side of the active matrix 100. And an etch stop layer 115 formed on the protective layer 110.

The actuator 200 has one side in contact with the etch stop layer 115 and the other side of the support layer 125 and the upper portion of the support layer 125 formed in parallel with the bottom of the active matrix 100 via the air gap 160. A lower layer 130 formed on the lower layer 130, a strained layer 135 formed on the upper portion of the lower electrode 130, an upper electrode 140 formed on the upper portion of the strained layer 135, and a strained layer from one side of the strained layer 135. 135, a via hole 145 formed to an upper portion of the drain pad 105 through the lower electrode 130, the support layer 125, the etch stop layer 115, and the protective layer 110, and the via hole 145. The via contact 150 is formed to connect the lower electrode 130 and the drain pad 105 therein.

In addition, referring to Figure 4, the plane of the support layer 125, one side has a concave portion of the rectangular shape in the center, the concave portion is formed in a shape that widens stepwise toward both edges, the other side is Corresponding to the concave portion has a quadrangular protrusion that narrows stepwise toward the center portion. Therefore, the protruding portion of the support layer of the actuator adjacent to the concave portion of the support layer 125 is fitted, and the rectangular projection is fitted into the concave portion of the support layer of the adjacent actuator. The support layer 125 of the present invention performs the function of the membrane 30 described in the preceding application.

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

7A to 7D show a manufacturing process diagram of the thin film type optical path control device shown in FIG. 7A to 7D, the same reference numerals are used for the same members as in FIG.

Referring to FIG. 7A, a drain pad 105 is formed on an active matrix 100 having M × N MOS transistors (not shown) therein. The drain pad 105 is formed to have a thickness of about 4000 mm by using a metal such as tungsten or titanium. The drain pad 105 is applied from the outside to transfer the first signal transmitted through the MOS transistor embedded in the active matrix 100 to the via contact 150.

Subsequently, a protective layer 110 is formed on the drain pad 105 and the active matrix 100 to protect the active matrix 100 having the transistor embedded therein. The protective layer 110 is formed of phosphorous silicate glass (PSG) using a chemical vapor deposition (CVD) method. It is formed to have a thickness of about 0㎛. The protective layer 110 prevents the transistor embedded in the active matrix 100 from being damaged during subsequent processing.

An etch stop layer 115 is stacked on the passivation layer 110. The etch stop layer 115 is formed to have a thickness of about 1000 to 2000 GPa using nitride by low pressure chemical vapor deposition (LPCVD). The etch stop layer 115 prevents the active matrix 100 and the protective layer 110 from being etched due to a subsequent etching process.

The sacrificial layer 120 is stacked on the etch stop layer 115. The sacrificial layer 120 is formed of phosphorus silicate glass (PSG) containing phosphorus (P) in a high concentration so as to have a thickness of about 2.0 to 3.0 μm by an atmospheric chemical vapor deposition (APCVD) method. In this case, since the sacrificial layer 120 covers the upper portion of the active matrix 100 in which the transistor is embedded, the flatness of the surface thereof is very poor. Therefore, the surface of the sacrificial layer 120 is made to have a thickness of about 1 μm by using a spin on glass (SOG) method or a CMP method on the surface of the sacrificial layer 120. It is flattened by grinding. Subsequently, a portion of the sacrificial layer 120 where the drain pad 105 is formed is etched to expose a portion of the etch stop layer 115 to form a position where the support portion 200a of the actuator is to be formed.

Referring to FIG. 7B, a first layer 124 is stacked on the exposed etch stop layer 115 and the sacrificial layer 120. The first layer 124 is formed to have a thickness of about 0.1 to 1.0 μm using a low pressure chemical vapor deposition (LPCVD) method. The first layer 124 is later patterned into a support layer 125.

The lower electrode layer 129 is formed on the first layer 124 using a metal such as platinum, tantalum, or platinum-tantalum having excellent electrical conductivity. The lower electrode layer 129 is formed to have a thickness of about 0.01 to 1.0 µm using a sputtering method. Subsequently, the lower electrode layer 129 is iso-cutted so that the lower electrode layer 129 is applied with an independent first signal for each pixel. The lower electrode layer 129 is later patterned with the lower electrode 130 to which the first signal is applied. The first signal applied from the outside is applied to the lower electrode 130 through the transistor, the drain pad 105, and the via contact 150 embedded in the active matrix 100.

The second layer 134 is stacked on the lower electrode layer 129. The second layer 134 is formed using a piezoelectric material such as PZT or PLZT to have a thickness of 4000 to 6000 kPa, preferably about 4000 kPa. The second layer 134 is formed using a sol-gel method, a sputtering method, or a chemical vapor deposition (CVD) method, and then subjected to a phase change by heat treatment using a rapid heat treatment (RTA) method. Subsequently, the piezoelectric material constituting the second layer 134 is polarized. The second layer 134 is later patterned into the strained layer 135.

An upper electrode layer 139 is stacked on the second layer 134. The upper electrode layer 139 is formed of a metal having electrical conductivity and reflectivity such as aluminum, silver, or platinum so as to have a thickness of about 0.01 to 1.0 탆 using a sputtering method. Subsequently, the upper electrode layer 139 is patterned into a predetermined pixel shape to form the upper electrode 140. At this time, the upper electrode layer 139 is patterned in a swing shape so as not to pass through the support portion 200a of the actuator. The second signal is applied to the upper electrode 140 through a common electrode line (not shown) from the outside.

Referring to FIG. 7C, the second layer 134 is patterned to form a strained layer 135 having a pixel shape larger than that of the upper electrode 140. Referring to FIG. 7B, since the second layer 134 is formed on the first layer 124 and the lower electrode layer 129, a portion of the second layer 134 formed on the support part 200a of the actuator is It has a thickness (d ₁ + d ₂ ) of about 6000 to 8000 kPa from the etch stop layer 115 having the drain pad 105 formed below, but the remaining portion of the second layer 134 is about 4000 k (d _2). Thickness). As a result, when the second layer 134 is patterned into a predetermined pixel shape, the remaining portion of the second layer 134 is excessively excessive compared to the portion formed on the support portion 200a of the actuator. By etching, the lower electrode layer 129 formed under the etching may be etched and damaged. In addition, although the second layer 134 may be etched so that the lower electrode layer 129 is not damaged, the etching process is difficult to control the etching depth and the reproducibility of the etching process is very low so that the actuator of the second layer 134 may be etched. The portion formed on the supporting portion 200a has a problem that is not sufficiently etched.

Therefore, as shown in FIG. 7C, in the present invention, a portion of the second layer 134 formed on the support portion 200a of the actuator is first etched at about 2000 to 4000 mm (t ₁ thickness). The thickness of the second layer 134 is equal to the thickness of the remaining portion. Subsequently, since the second layer 134 etched to have a uniform thickness is patterned to a predetermined pixel shape, the etching depth is easier to control and the reproducibility of the etching process is increased. The strained layer 135 may be formed without damaging the 129.

Subsequently, the lower electrode layer 129 is patterned to form a lower electrode 130 having a pixel shape larger than that of the strained layer 135. When the second signal is applied to the upper electrode 145 and the first signal is applied to the lower electrode 135, an electric field is generated between the upper electrode 145 and the lower electrode 135. The deformation layer 140 causes deformation by this electric field.

Referring to FIG. 7D, the strained layer 135, the lower electrode 130, the first layer 124, the etch stop layer 115, and the protective layer from one side of the strained layer 135 to an upper portion of the drain pad 105. The via holes 145 are sequentially etched to form via holes 145. Accordingly, the via hole 145 is formed from one side of the strained layer 135 to an upper portion of the drain pad 105. Subsequently, a via contact 150 is formed by depositing a metal having excellent electrical conductivity such as tungsten (W), aluminum, or titanium (Ti) in the via hole 145 using a sputtering method. The via contact 150 electrically connects the drain pad 105 and the lower electrode 130. Therefore, the first signal applied from the outside is applied to the lower electrode 130 through the transistor, the drain pad 105, and the via contact 150 embedded in the active matrix 100. Subsequently, the first layer 124 is patterned into a predetermined pixel shape to form the support layer 125. Subsequently, the sacrificial layer 120 is etched using hydrogen fluoride (HF) vapor to form an air gap 160, followed by rinsing and drying to complete the AMA device.

In the above-described thin film type optical path control device according to the present invention, the first signal transmitted from the outside through the pad of the TCP and the pad of the AMA panel is a transistor, a drain pad 105 and a via contact (embedded in the active matrix 100). It is applied to the lower electrode 130 which is a signal electrode through the 150. At the same time, a second signal is applied to the upper electrode 140 from the outside through a pad of TCP, a pad of an AMA panel, and a common electrode line to generate an electric field between the upper electrode 140 and the lower electrode 130. Due to this electric field, the deformation layer 135 formed between the upper electrode 140 and the lower electrode 130 causes deformation. The strained layer 135 is contracted in a direction perpendicular to the electric field, and thus the actuator 200 is bent at a predetermined angle. Since the upper electrode 140, which also functions as a mirror that reflects the light beam, is formed on the actuator 200, the upper electrode 140 is inclined together with the actuator 200. Accordingly, the upper electrode 140 reflects the light incident from the light source at a predetermined angle, and the reflected light passes through the slit to form an image on the screen.

In the manufacturing method of the thin film type optical path control apparatus according to the present invention, in order to reduce the step difference between the support portion and the other portion of the actuator by first etching the portion formed on the support portion of the actuator of the deformation layer by patterning the remaining portion in the pixel shape The thickness of the strained layer can be made uniform at the support portion of the actuator and at other portions. Therefore, it is possible to prevent the lower electrode from being damaged by excessive etching due to the imbalance of the strain layer thickness. In addition, it is possible to easily control the etching depth and to increase the reproducibility of the etching process.

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

Claims (3)

Providing an active matrix having M × N (M, N is an integer) transistors and having drain pads formed on one side thereof; And Iii) laminating a first layer such that one side is in contact with the top of the active matrix and the other side is parallel to the bottom of the active matrix, ii) laminating a bottom electrode layer on top of the first layer, iii) the bottom Stacking a second layer on top of the electrode layer, iii) forming an upper electrode layer on top of the second layer, iii) patterning the upper electrode layer to form an upper electrode, iii) out of the second layer Forming a strained layer including first patterning a portion of the first layer in contact with the active matrix and second patterning the second layer; iii) patterning the bottom electrode layer to form a bottom electrode And iii) forming an actuator comprising the step of patterning the first layer to form a support layer. The method of claim 1, wherein the first patterning of the second layer comprises: the thickness of the second layer in the portion where the first layer is in contact with the active matrix and the thickness of the second layer in the other portion are the same. Method of manufacturing a thin film type optical path control device, characterized in that the step of performing. The method of claim 1, wherein the first patterning of the second layer comprises etching 2000 to 4000 μs of a portion of the second layer in contact with the active matrix. Method of manufacturing the device.

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