KR100207371B1 - Fabrication method for lightpath modulation device - Google Patents

Abstract

The present invention relates to a method for manufacturing the optical path control device (500), comprising the steps of forming a first sacrificial layer (200) on a drive substrate 130 having an electrically connected connection terminal 150, and a nitride or oxide A process of forming the support part 120, a process of forming a plug 115 made of tungsten or titanium in the groove of the support part 120, and an electrical signal with the connection terminal 150 on the driving substrate 130. A process of forming the electrode 160, a process of forming the deformation unit 170 of ceramic material, a process of electrically connecting the connection terminal 150 on the driving substrate to form the bias electrode 190, and a first process The process of forming the second sacrificial layer 300 of the same material as the sacrificial layer 200, the process of forming the elastic portion 180 by applying nitride or oxide, and the mirror 110 with a metal having good reflection characteristics Forming process and the pixel pattern of the mirror 110. The process of forming a predetermined groove by performing a resist and etching, and removing the sacrificial layers (200, 300) for the air gap between the support portion 120, providing a stable optical path control device And it provides an optical path control device with a fast response speed when driving.

Description

Manufacturing method of optical path control device

1 is a plan view of a conventional optical path control device.

2 is a cross-sectional view of a conventional optical path control device.

3 is a plan view of an optical path control apparatus according to an embodiment of the present invention.

4 is a perspective view of the optical path control apparatus according to the embodiment of FIG.

Figure 5 is a flow chart of the manufacturing process of the optical path control apparatus according to an embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

110: mirror 115: plug

120: support 130: drive substrate

150: connection terminal 160: signal electrode

170: deformation portion 180: elastic portion

190: bias electrode 200, 300: sacrificial layer

400: actuator 500: optical path control device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an optical path control device for use in a projection type image display device, and more particularly, to a method of manufacturing an optical path control device made of a thin film ceramic.

An image display apparatus is classified into a direct view type image display apparatus and a projection type image display apparatus according to a display method. The direct view type image display apparatus includes a CRT (Cathode Ray Tube), but such a CRT image display apparatus has high image quality but has a problem of increasing weight and thickness and cost as the screen is enlarged. . Projection type image display apparatuses include a large screen liquid crystal display (hereinafter, referred to as an LCD), and such large screen LCDs can be thinned to reduce weight. However, such LCDs have a high loss of light due to the polarizing plate, and thin film transistors for driving the LCD are formed for each pixel, so that there is a limit in increasing the aperture ratio (light transmission area).

In order to make up for the shortcomings of LCDs, a projection image display device using Actuated Mirror Arrays (hereinafter referred to as AMA) has been developed by Aura, USA. Projection type image display device using AMA The white light emitted from the light source is separated into red, green, and blue light beams, and then these light beams are reflected on reflectors inclined by the deformation of the actuators, respectively. ), And adjust the amount of light of these luminous fluxes to project on the screen. The AMA is classified into a one-dimensional AMA having an actuator of M × 1 and a two-dimensional AMA having an M × N according to the driving method. The actuator includes a deformable part and electrodes formed of a piezoelectric material or a warping material, and deforms at an electric field to tilt the mirror on the top.

1 is a plan view of a conventional optical path control device 50.

2 is a cross-sectional view of a conventional optical path control device 50.

The conventional optical path control apparatus 50 includes a driving substrate 11, a support portion 27, an actuator 30 and a mirror (29).

The driving substrate 11 is made of glass or alumina (Al ₂ O ₃ ), etc., made of an insulating material or a semiconductor such as silicon, and M × N transistors (not shown) are embedded in a matrix form. Connection terminals 13 electrically connected to the transistors are formed.

The actuator 30 includes a deformable portion 17, a signal electrode 19, a plug 15, a bias electrode 23, and an elastic portion 25.

The deformable part 17 is formed of an electrostrict ceramic or a piezoelectric ceramic polarized in opposite directions along a vertical axis. The deformable part 17 includes a signal electrode 19 on a lower surface of the deformable part 17 and a bias electrode on an upper surface thereof. 23) is formed. The signal electrode 19 is electrically connected to the connection terminal 13 of the driving substrate 11 and is spaced apart from the signal electrodes of adjacent actuators from an external circuit (not shown) through the transistors and the connection terminal 13. Image signals are input. The elastic part 25 is formed on the upper surface between the signal electrode 19 and the support part 27 on one side of the lower side.

The mirror 29 is formed of a metal having good reflection characteristics, and reflects by changing the path of incident light. In order to form a natural image by maintaining the continuity of colors when forming an image by the light reflected by the mirror 29, adjacent actuators should be configured in the same direction even if there is a difference in the inclination angle. Therefore, image signals having different phases are input to the actuators adjacent to the actuator 30. As shown in FIG. 2, the support part 27 is fixed between one side surface of the actuator 30 and the driving substrate 11.

However, the conventional optical path control device 10 is a structural problem that the bending of the actuator 30 is caused by the weight or stress of the actuator 30 because the support portion 27 is fixed to the inner side of the actuator 30 There is this.

In addition, when the actuator 30 is driven, the mirror 29 surface is not flat, and thus there is a problem in that light efficiency is lowered.

In addition, in the conventional optical path control apparatus 10, as shown in FIG. 2, since the support part 27 is fixed to one side of the actuator 30, there is a problem that the response speed is slow because of the rigidity during driving.

An object of the present invention is to solve the conventional problems as described above, to provide a method for manufacturing a stable optical path control apparatus for driving a pixel divided into two in the integrated mirror in order to prevent the deflection of the mirror by stress or self-weight. It is.

Another object of the present invention is to provide a method of manufacturing an optical path control device for keeping the reflective surface of the mirror in a flat state.

Still another object of the present invention is to provide a method for manufacturing an optical path control apparatus having a fast response speed during driving.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3 is a plan view of an optical path control apparatus according to an embodiment of the present invention.

4 is a perspective view of the optical path control apparatus according to the embodiment of the present invention, and is a view showing the X-axis cut in FIG. The optical path control apparatus 500 of the present invention shown in FIG. 4 includes a driving substrate 130, an actuator 400, and a mirror 110.

5 is a cross-sectional view showing a manufacturing process of the optical path control apparatus according to the embodiment of the present invention.

The driving substrate 130 shown in FIG. 4 is made of an insulating material such as glass, alumina (Al ₂ O ₃ ), or a semiconductor such as silicon, and M × N transistors (not shown) are formed in a matrix form. It is built in. In addition, the transistors are electrically connected to the signal electrode 160 and the bias electrode 190 on the surface of the driving substrate 130.

The actuator 400 includes a bias electrode 190, a support 120, a deformation unit 170, a signal electrode 160, a connection terminal 150, and a bullet unit 180, and adjacent actuators (not shown). It is separate from the fields.

On the other hand, the support 120 is formed to cover the bias electrode 190 on the driving substrate 130, the material is usually coated with a ceramic of nitride (Nitride) or oxide (Oxide). The bias electrode 190 is formed on the support part 120 using platinum, silver, or aluminum.

The connection terminal 150 is fixed to the driving substrate 130 and serves to electrically connect the signal electrode 160 and the bias electrode 190 during driving. The electrode terminal separator 155 of the connection terminal 150 is an insulator that electrically separates the signal electrode 160 and the bias electrode 190.

The signal electrode 160 is formed on the upper surface of the support 120, and is electrically connected to the connection terminal 150 and formed of platinum, silver, aluminum, or the like having good conductivity.

The deformable portion 170 is formed on the upper surface of the signal electrode 160 and is made of piezoelectric ceramic or electrodistorical ceramic, and deforms when the electric field is generated to tilt the mirror 110 on the upper side.

The bias electrode 190 is formed as a thin film on the upper surface of the deformable portion 170 and is electrically connected to the connection terminal 150 on the driving substrate 130. The bias electrode 190 is made of platinum, silver, aluminum, or the like.

The elastic part 180 is formed of a nitride or an oxide, in particular silicon nitride, which is the same material as that of the support part 120 by sputtering or chemical vapor deposition (CVD) between the bias electrode 190 and the mirror 110. It is formed by applying (Si ₃ N ₄ ).

The mirror 110 is formed on the upper surface of the elastic portion 180 by applying a metal having good reflecting properties such as aluminum and silver to a thickness of about 500 to 2000 Pa by sputtering or CVD. On the other hand, when the deformation unit 170 is deformed when the electric field is generated, the mirror 110 is also inclined.

On the other hand, the manufacturing process of the optical path control device 500 of the present invention will be described with reference to FIG.

Step 1. Form the sacrificial layer 200 and process the support 120

First, as shown in (a) of FIG. 5, PSG, silicon oxide, low temperature oxide, and the like for forming the actuator 400 and the mirror 110 on the driving substrate 130 having the independent connection terminal 150, The sacrificial layer 200 is formed using a material such as silicon, molybdenum, copper, iron, and chromium nickel. When the sacrificial layer 200 is formed, a photoresist and an etching process are performed on the support 120.

Step 2. Form the support 120, the plug 115 and the signal electrode 160.

① As shown in (b) of FIG. 5, the support 120 is formed of a ceramic material of nitride (for example, silicon nitride (Si ₃ N ₄ )) or an oxide by a method such as sputtering or CVD. do.

② When the support part 120 is formed, the plug 115 is electrically deposited with the connection terminal 150 on the driving substrate 130 by depositing tungsten or titanium for the electrical connection between the signal electrode 160 and the bias electrode 190. It is formed by connecting. Then, the surface is planarized by etch back or spin on glass (SOG) and the unnecessary electrode material is removed.

③ The signal electrode 160 is formed by applying platinum or titanium on the sacrificial layer 200 and the support 120 by sputtering or CVD. A liftoff photoresist is used to protect the bias electrode 190. Method as shown in Fig. 5B.

Step 3. Form Deformation 170 and Bias Electrode 190

① As shown in (c) of FIG. 5, the deformable portion 170 is formed on the signal electrode 160 by BaTiO ₃ , PZT (Pb (Zr ₁ , Ti) O ₃ ) or PLZT ((Pb, La) ( Piezoelectric ceramics such as Zr, Ti) O ₃ ), or electrodistorical ceramics such as PMN (Pb (Mg, Nb) O ₃ ) may be formed in a thickness of about 0.7 to 2 μm by the Sol-gel method, sputtering, or CVD. Is formed.

② Then, the photoresist process and etching are performed to electrically connect the bias electrode 190 to connect the plug 115 between the deformable portions 170 to the bias electrode 190.

(3) The bias electrode 190 is formed by applying a conductive metal such as gold, platinum, silver or aluminum to the upper surface of the deformable portion 170 by sputtering or CVD.

Step 4. Forming the second sacrificial layer 300, the elastic portion 180 and the mirror 110

① As shown in (d) of FIG. 5, after the bias electrode 190 is formed, the photoresist process and the upper portion of the first sacrificial layer 200 in the bias electrode 190 for patterning the actuator 400. After etching to the surface, the second sacrificial layer 300 is formed to form the elastic part 180 and the mirror 110. The second sacrificial layer 300 is made of the same material as the first sacrificial layer 200 and is made of PSG, silicon oxide, low temperature oxide, silicon, molybdenum, copper, iron, chromium, nickel, or the like.

(2) The elastic part 180 is formed by applying nitride or oxide to the upper surface of the bias electrode 190 by sputtering or CVD, as shown in FIG.

(3) The mirror 110 is formed by sputtering or CVD on a metal having good reflective properties such as aluminum or silver on the upper surface of the elastic portion 180, as shown in FIG. Thereafter, the upper surface of the formed mirror 110 is planarized.

Step 4. Perform photoresist and etching and remove sacrificial layers 200,300

① When the mirror 110 is formed, photoresist and etching are performed to form a predetermined groove to the upper surface of the second sacrificial layer 300 for the pixel pattern of the mirror 110.

② Then, as shown in (e) of FIG. 5 between the support portions 120, the sacrificial layers 200 and 300 are removed using a solvent (eg, hydrogen fluoride (HF)) for an air gap. If all the manufacturing process of the optical path control device 500 is completed.

In the optical path control apparatus 500 of the present invention which has been subjected to the manufacturing process as described above, since the support part 120 is located at the center of the actuator 400, the reflective surface of the mirror 110 can be used in a flat state. The response speed is high because of the rigidity during driving. In addition, since the pixels of one mirror 110 are driven in two, they are structurally stable.

Claims (10)

A first step of forming a first sacrificial layer 200 using a material of any one of silicon molybdenum oxide, low temperature oxide, copper, iron, and chromium nickel on a driving substrate having transistors and connecting terminals electrically connected thereto; A second step of forming a support part (120) from nitride or oxide on a drive substrate having the electrically connected connection terminal; A third step of electrically connecting the connection terminal to the driving substrate and forming a plug 115 made of tungsten or titanium in a groove of the support part 0 (120); Sputtering or chemical vapor deposition (hereinafter, referred to as CVD) on the first sacrificial layer 200 and the support part 120 to apply metal to electrically connect the connection terminals to the driving substrate. A fourth step of forming the signal electrode 160; A fifth step of forming a deformable portion 170 by coating a ceramic material on the signal electrode 160; A sixth step of electrically connecting the connection terminal on the driving substrate through the plug 115 to form a bias electrode 190 made of a conductive thin film of metal; A seventh process of forming a second sacrificial layer 300 by performing a photoresist process and then etching from the bias electrode 190 to an upper surface of the first sacrificial layer 200; ; An eighth step of forming an elastic part 180 by applying nitride or oxide to upper surfaces of the bias electrode 190 and the second sacrificial layer 300; A ninth step of forming a mirror (110) on the upper surface of the elastic portion (180) by sputtering or CVD with a metal having good reflection characteristics; A tenth step of performing photoresist and etching to the upper surface of the second sacrificial layer (300) for the pixel pattern of the mirror (110); The manufacturing method of the optical path control device to perform the eleventh process of removing the sacrificial layer (200,300) using a solvent for the air gap between the support (120). The method of claim 1, wherein the second step is to form the support part by sputtering or CVD. The method of claim 1, wherein the third process further comprises performing an etch back or spin on glass (SOG) method to form the plug 115. The method of claim 1, wherein the fourth process comprises forming the signal electrode (160) made of a metal of platinum or titanium. The method of claim 4, wherein the fourth process further comprises performing a liftoff method and a photoresist method to form the signal electrode. The optical path control method of claim 1, wherein the fifth process comprises applying a piezoelectric ceramic or an electrostrictive ceramic material by a Sol-Gel, sputtering, or CVD method to form the deformation part 170. Method of manufacturing the device. The method of claim 1, wherein the sixth step comprises applying the material of gold, platinum, silver, or aluminum by sputtering or CVD to form the bias electrode (190). The method of claim 1, wherein the seventh step is to form a second sacrificial layer (300) made of the same material as the first sacrificial layer (200). The method of claim 1, wherein the eighth step is to form the elastic portion (180) by sputtering or chemical vapor deposition (CVD). The method of claim 1, wherein the ninth step is to form the mirror (110) made of silver or aluminum.