KR102579089B1 - Method for Manufacturing a Wire Grid Polarizer Using Ion Beam Sputtering Device - Google Patents

Abstract

The present invention can coat the reflection and absorption film of a large-area polarizing filter by applying a linearly focused ion beam source and a flat sputtering target mounted on a cylindrical or polygonal pillar, and can reduce the consumption rate of the sputtering target while reducing the amount of deposition material. It relates to a method of manufacturing a polarizing filter using an ion beam sputtering device that can be uniformly deposited on a polarizing grid, an anisotropic process is possible in a high vacuum environment, and in-line large-area mass production is possible.

Description

Method for manufacturing a polarizing filter using an ion beam sputtering device {Method for Manufacturing a Wire Grid Polarizer Using Ion Beam Sputtering Device}

The present invention relates to a method of manufacturing a polarizing filter using an ion beam sputtering device. More specifically, the present invention relates to a method of manufacturing a polarizing filter using an ion beam sputtering device. More specifically, the present invention relates to a method of manufacturing a polarizing filter using a linearly focused ion beam source and a flat sputtering target mounted on a cylindrical or polygonal pillar to form a reflection and absorption film of a large-area polarizing filter. A polarization filter using an ion beam sputtering device that can be coated, reduces the consumption rate of the sputtering target, allows the deposition material to be deposited uniformly on multiple polarization grids, allows an anisotropic process in a high vacuum environment, and enables in-line large-area mass production. It is about manufacturing method.

In general, polarizing films are widely used to improve the image characteristics of liquid crystal display devices. Recently, liquid crystal display devices use a wire grid polarizing film formed with a light-absorbing coating film that absorbs only specific wavelengths in the light region to suppress the phenomenon of color purity deterioration. In other words, an attempt is made to realize high color reproducibility by giving the polarizing film a function as a second color filter.

Korean Patent Publication No. 10-2017-0023826 (Wire Grid Polarizer with Dual Absorptive Regions) discloses a selectively absorptive wire grid polarizer. An incoming wire grid polarizer disposed between the light source and the liquid crystal display transmits one polarization (e.g., p-polarized light) and reflects the opposite polarization (e.g., s-polarized light). Light reflected from the incoming wire grid polarizer can adversely affect the projected image (e.g., ghosting). However, an absorptive coating formed on the incoming wire grid polarizer absorbs light reflected from the liquid crystal display.

Meanwhile, deposition devices for forming thin films typically include deposition devices using electron beams and sputtering devices using ion beams. A deposition device using an electron beam irradiates electrons accelerated by a predetermined voltage to the material in a crucible placed in a vacuum container and heats it to evaporate the material, and this evaporated material is deposited on the substrate placed in the vacuum container. It attaches to the surface to form a thin film.

A deposition device using such an electron beam has a very high target raw material consumption rate, and non-uniformity occurs in which the deposition material is not uniformly coated on the substrate. Accordingly, it is difficult to coat the reflection and absorption films of large-area polarizing filters by applying a deposition device using an electron beam.

Meanwhile, in Korean Patent Publication No. 10-1998-055989 (ion beam sputtering deposition apparatus), the deposited object (sputtering target) is configured to rotate by a rotating means. As the ion beam emitted from the ion gun is irradiated uniformly on the entire surface of the rotating deposition target (sputtering target), the deposition target (sputtering target) is uniformly sputtered.

In the prior art, as the sputtering process progresses, the outer diameter of the target gradually becomes smaller, and the focal position of the ion beam output to the sputtering target and the incident angle of the deposition material incident on the polarization grid after sputtering from the target also change. If the incident angle of the deposition material changes, the transmission and polarization quality may change, which may result in deterioration of the quality of the polarization filter.

Korean Patent Publication No. 10-2017-0023826 (Wire grid polarizer with double absorptive regions) Korean Patent Publication No. 10-1998-055989 (Ion beam sputtering deposition device)

The present invention is intended to solve these problems of the prior art,

First, the reflection and absorption films of a large-area polarizing filter can be coated by applying a linearly focused ion beam source and a flat sputtering target mounted on a cylindrical or polygonal pillar.

Second, while lowering the consumption rate of the sputtering target, the deposition material can be deposited uniformly on multiple polarization gratings.

Third, we aim to provide a polarizing filter manufacturing method using an ion beam sputtering device that enables an anisotropic process in a high vacuum environment and enables in-line large-area mass production.

The method of manufacturing a polarizing filter using an ion beam sputtering device according to the present invention includes the steps of laminating at least one pair of optical layers on a base substrate, forming a polarizing grid, coating a reflective thin film on the top of the polarizing grid, and the reflective thin film. It may include the steps of coating a blackening thin film and removing the remaining film remaining between the polarizing grids.

The step of laminating at least one pair of optical layers on a base substrate may include laminating at least one pair of optical layers composed of alternating low-refractive materials and high-refractive materials on the base substrate. The base substrate may be implemented as, for example, a glass substrate.

In the step of forming the polarization grid, the polarization grid may be formed by patterning a coating layer laminated on the base substrate using an imprint method.

The step of coating a reflective thin film on the upper part of the polarizing grid can be done by inserting the polarizing grid into a vacuum chamber equipped with a sputtering device using an ion beam, and then coating the upper part of the polarizing grid with a sputtered deposition material to coat the reflective thin film.

In the step of coating the blackening thin film on the reflective thin film, the blackening thin film may be coated on the reflective thin film formed on the polarizing grid.

In the step of removing the remaining film remaining between the polarization gratings, the remaining film may be removed using ion beam milling, ICP method, or RIE method.

In the present invention, in the step of coating a reflective thin film by placing a polarizing grid in a vacuum chamber equipped with a device for sputtering using an ion beam and then coating the top of the polarizing grid with a sputtered deposition material, the device for sputtering using an ion beam is sputtering. It can be configured to include a target, a focused ion beam generator, a shutter, a shutter control unit, a main control unit, a shielding mask, a transfer tray, and a driving unit.

The sputtering target is implemented as a flat plate mounted on a cylindrical or polygonal pillar, and the ion beam collides with the surface to release the sputtered deposition material. The sputtering target consists of a holder to which the target is attached and a holder supporter that supports the holder, and a rotation means for rotating the holder may be provided on the holder supporter.

The focused ion beam generator generates plasma ions, focuses the generated ions, and outputs them to the sputtering target as a linear focused ion beam, with an incident angle of 60 degrees or more and 85 degrees based on the plane perpendicular to the target surface on which the ion beam enters. Output the ion beam so that it becomes below.

The shutter blocks the deposition material emitted from the sputtering target. The shutter control unit inserts or removes the shutter between the sputtering target and the transfer tray. The main control unit may transmit a shutter insertion signal or a shutter release signal to the shutter control unit.

The transfer tray transfers the substrate on which the polarization grid is formed. The driving unit drives the transfer tray in a certain direction.

The transfer tray may be controlled by the main control unit so that the substrate on which the polarization grid is formed is transferred at an angle of 10 degrees or more and 20 degrees or less with respect to the horizontal axis.

A shielding mask is placed between the shutter and the transfer tray, and a slit through which the deposition material passes is formed.

The thickness of the reflective thin film formed by the polarizing filter manufacturing method using the ion beam sputtering device of the present invention is 0.2 μm or more and 0.5 μm or less, and the thickness of the blackening thin film is 0.2 μm or more and 0.5 μm or less.

According to the method of manufacturing a polarizing filter using the ion beam sputtering device of the present invention having this configuration, a focused ion beam generator and a flat sputtering target mounted on a cylindrical or polygonal pillar are applied to coat the reflection and absorption film of the large-area polarizing filter. can do.

The focused ion beam generator of the present invention is implemented to output an ion beam so that the incident angle is 60 degrees or more and 85 degrees or less based on the plane perpendicular to the target surface on which the ion beam is incident, thereby achieving high sputtering yield. . In other words, there is an effect of coating a large amount of target material with the same power.

In addition, according to the method of manufacturing a polarizing filter using the ion beam sputtering device of the present invention, a shielding mask with a slit through which the deposition material passes is disposed between the shutter and the transfer tray, so that impurities are first filtered by the shutter and secondarily a shielding mask. By filtering out impurities, sputtering molecular materials optimal for thin film characteristics can be uniformly deposited.

In addition, according to the polarizing filter manufacturing method using the ion beam sputtering device of the present invention, the ion beam is output to the sputtering target so that the incident angle is 60 degrees or more and 85 degrees or less, and the sputtered deposition material is controlled through the shutter to form a plurality of polarization gratings. The deposition material can be deposited uniformly.

As the sputtering process progresses, the outer diameter of the target gradually decreases, and the focal position of the ion beam output to the target and the incident angle of the deposition material incident on the polarization grating after sputtering from the target also change. To solve this problem, the transfer tray is controlled by the main control unit so that the substrate on which the polarization grid is formed is transferred at an inclination of 10 degrees or more and 20 degrees or less with respect to the horizontal axis, so that the angle of incidence of the coating material can be compensated for by the inclination of the transfer tray. In other words, an anisotropic process is possible in a high vacuum environment, and in-line large-area mass production is possible.

Figure 1 is an exemplary diagram for explaining a method of manufacturing a polarizing filter using an ion beam sputtering device according to the present invention.
Figure 2 is a first embodiment for explaining the main configuration of the ion beam sputtering device for manufacturing a polarizing filter according to the present invention.
Figure 3 is an exemplary diagram for explaining a polarizing grid coated with a deposition material by an ion beam sputtering device for manufacturing a polarizing filter according to the present invention.
Figure 4 is a second embodiment for explaining the main configuration of the ion beam sputtering device for manufacturing a polarizing filter according to the present invention.

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

Figure 1 is an exemplary diagram for explaining a method of manufacturing a polarizing filter using an ion beam sputtering device according to the present invention.

As shown in Figure 1, the method of manufacturing a polarizing filter using the ion beam sputtering device of the present invention includes the steps of preparing a base substrate (a), stacking at least one pair of optical layers on the base substrate (b), Forming a polarizing grid (c), coating a reflective thin film on the polarizing grid (d), coating the reflective thin film with a blackening thin film (e), removing the residual film remaining between the polarizing gratings (f) ) can be configured including.

In step (a) of preparing the base substrate, the base substrate 101 may be a substrate made of a non-conductive material, for example, glass, PC, PI, or PET. The base substrate 101 may be configured in the form of a plate with a predetermined thickness and width.

The step (b) of laminating at least one pair of optical layers on the base substrate includes at least one pair of optical layers composed of alternating low-refractive materials 102 and high-refractive materials 103 on the base substrate 101. More than one layer can be stacked.

The low refractive material 102 has a refractive index n of less than 2.1, preferably between 1.9 and 2.1. The low refractive index material 102 preferably contains at least one oxide, for example SiO ₂ or tin oxide and/or one nitride, particularly preferably silicon nitride.

The high refractive material 103 has a refractive index of 2.1 or more, and the material is for example MnO, WO ₃ , Nb ₂ O ₅ , Bi ₂ O ₃ , TiO ₂ , Zr ₃ N ₄ and/or AlN, preferably silicon- It may be a metal mixed nitride, such as silicon-aluminum mixed nitride, silicon-hafnium mixed nitride, or silicon-titanium mixed nitride. Silicon-titanium mixed nitrides are particularly advantageous in terms of sheet resistance for electrically conductive coatings. The silicon-zirconium mixed nitride preferably has a dopant. High refractive index material 103 may contain, for example, aluminum-doped silicon-zirconium mixed nitride.

In the step (c) of forming the polarization grid, the polarization grids 102 and 103 may be formed by patterning the optical layer laminated on the base substrate 101 using an imprint method.

Imprint equipment for implementing nanoscale lithography is classified into two types. One is a heating technology using heat, and the other is an optical technology using ultraviolet (UV) light. While the heating technology has limitations in the temperature conditions that it can be used in an environment maintaining a temperature condition of 100℃ or higher, the optical technology using ultraviolet rays (UV) has environmental differences in terms of processing temperature in that it can be used even at room temperature.

Nanoimprint lithography technology using ultraviolet rays (UV) uses low-viscosity photocurable synthetic resin and ultraviolet rays (UV) to harden it, so it has the advantage of being suitable for multi-layer processes and mass production as it enables room temperature and low pressure processes. The present invention adopts a method of transferring structured nanopatterns using ultraviolet (UV) light among nanoimprint lithography technologies.

The step (d) of coating a reflective thin film on the upper part of the polarizing grating is by inserting the polarizing grating (102, 103) into a vacuum chamber equipped with a sputtering device using an ion beam, and then coating the sputtered deposition material on the upper part of the polarizing grating (102, 103). A reflective thin film 104 may be coated. The detailed configuration of the device for sputtering the polarization gratings 102 and 103 using an ion beam will be described in detail later with reference to FIGS. 2 to 4.

In the step (e) of coating the blackening thin film on the reflective thin film, the blackening thin film 105 may be coated on the reflective thin film formed on the polarizing grid. Carbon, copper oxide, chromium oxide, etc. can be used as the blackening thin film material.

In the step (f) of removing the remaining film 106 remaining between the polarization gratings, the remaining film may be removed using ion beam milling, ICP method, or RIE method.
In the process of Figure 1 (not shown), the ion beam sputtering device of the present invention is used.
One polarizing filter manufacturing method involves preparing a base substrate (a), polarizing light on the base substrate.
Step (b) of forming a grid, stacking at least one pair of optical layers on top of the polarization grid.
It may include a step (c), a step (d) of coating a reflective thin film or a blackening thin film on the top of the optical layer, and a step (e) of removing the residual film remaining between the polarizing gratings.

delete

Figure 2 is a first embodiment for explaining the main configuration of the ion beam sputtering device for manufacturing a polarizing filter according to the present invention.

As shown in Figure 2, the ion beam sputtering device for manufacturing a polarizing filter according to the present invention includes a sputtering target 110, a focused ion beam generator 120, a shutter 130, a shielding mask 140, and a transfer tray 150. It can be configured including.

The ion beam sputtering device for manufacturing a polarizing filter according to the present invention is configured in a vacuum chamber forming a sealed space therein. A vacuum pump that controls the degree of vacuum in the internal space may be coupled to one side of the vacuum chamber. It may be desirable to minimize oxygen content in the vacuum chamber by increasing the vacuum level. Depending on the process, non-reactive gas or reactive gas is injected into the vacuum chamber. Non-reactive gases include, for example, Ar, Ne, He, and Xe, and reactive gases include N ₂ , O ₂ , CH ₄ , and CF ₄ . In some cases, a mixture of non-reactive gas and reactive gas is used.

The sputtering target 110 is implemented as a flat plate mounted on a cylindrical or polygonal pillar, and the ion beam collides with the surface to emit sputtered deposition material. Targets or evaporation materials include silicon (Si), yttrium (Y), aluminum (Al), copper (Cu), silver (Ag), titanium (Ti), magnesium (Mg), neodymium (Nd), and tantalum (Ta). ), zirconium (Zr), chromium (Cr), nickel (Ni), iron (Fe), molybdenum (Mo), tungsten (W), cobalt (Co), zinc (Zn), tin (Sn), indium (In) ), gallium (Ga), selenium (Se), etc. can be used. The sputtering target 110 consists of a holder to which the target is attached and a holder supporter that supports the holder, and a rotation means for rotating the holder may be provided on the holder supporter.

When using a flat target, it can be a single flat surface or a polygonal pillar shape with four or more sides. One independent flat target material on one side can be attached and detached using a clamp. In the case of a polygonal pillar shape, targets of the same material or different materials are independently mounted on each side, and when changing targets, the target can be changed by rotating the polygonal pillar without breaking the vacuum. The back of the target can be cooled by flowing coolant. Preferably, the polygonal column-shaped target attachment surface may be 4 or more and 8 or less.

The focused ion beam generator 120 generates ions (plasma ions) from a neutral gas in a vacuum chamber, focuses the generated ions, and emits them to the sputtering target 110 as a linear focused ion beam. The focused ion beam generator 120 may use, for example, an endhole ion source. The endhole ion source can form an acceleration loop inside, including magnetic poles and electrodes. When a positive high voltage is applied to the electrode, internal electrons inside the vacuum chamber or plasma electrons move toward the counter electrode in the acceleration loop space of the endhole ion source. At this time, the internal electrons or plasma electrons receive force from the magnetic field generated between the electrodes and move at high speed along the closed loop. Electrons in the closed loop ionize the neutral gas in the loop, and positive ions among the ionized plasma ions move toward the cathode where the sputtering target 110 is located by the potential difference between the electrode and the sputtering target 110 to the sputtering target 110. They collide at high speeds, and as a result, atoms on the surface of the sample may be sheared off.

The focused ion beam generator 120 outputs a linearly focused ion beam to the sputtering target 110, and outputs the ion beam so that the angle of incidence is 60 degrees or more and 85 degrees or less based on the plane perpendicular to the target surface on which the ion beam enters. do. The focused ion beam generator 120 of the present invention is implemented to output an ion beam such that the incident angle is 60 degrees or more and 85 degrees or less based on the plane perpendicular to the target surface on which the ion beam is incident, thereby achieving a relatively high sputtering yield. ) and has the advantage of coating a large amount of target material with the same power.

If the incident angle is less than 60 degrees or more than 85 degrees based on the plane perpendicular to the target surface on which the ion beam is incident, insufficient energy to tear off the target surface atoms is incident on the target surface, lowering the sputtering yield. decreases sharply.

The shutter 130 blocks the deposition material emitted from the sputtering target 110. The shutter 130 may be configured in a plate shape. The shutter 130 may be inserted or removed between the sputtering target 110 and the transfer tray 150 by the shutter control unit. The shutter control unit may include a motor that rotates the shutter 130. The shutter control unit receives a shutter insertion signal or a shutter release signal from the main control unit. For example, the main control unit may transmit a shutter insertion signal or a shutter release signal to the shutter control unit based on the type of material emitted from the sputtering target 110.

The shielding mask 140 is disposed between the shutter 130 and the transfer tray 150, and a slit 141 through which the deposition material passes is formed. By placing a shielding mask 140 with a slit 141 through which the deposition material passes between the shutter 130 and the transfer tray 150, impurities are first filtered by the shutter 130 and secondarily the shielding mask 140 ), impurities are filtered out, and only the deposition material can be uniformly deposited (coated) on multiple polarization grids.

The transfer tray 150 transfers the substrate on which the polarization grid is formed. The transfer tray 150 is driven in a certain direction by a driving unit.

Figure 3 is an exemplary diagram for explaining a polarizing grid coated with a deposition material by the ion beam sputtering device for manufacturing a polarizing filter according to the present invention, and Figure 4 is an illustration for explaining the main configuration of the ion beam sputtering device for manufacturing a polarizing filter according to the present invention. This is the second embodiment.

As shown in FIG. 3, the deposition (coating) material emitted from the sputtering target is deposited on the polarization grid to form a coating film. As the sputtering process progresses, the outer diameter of the sputtering target 110 gradually decreases, and the focus position of the ion beam output to the sputtering target 110 and the deposition (coating) material incident on the polarization grid after sputtering from the sputtering target 110 The angle of incidence also changes. Since the transmission and polarization quality of the polarization grating varies depending on the incident angle (ϕ) of the deposition (coating) material, the incident angle (ϕ) of the deposition (coating) material must be compensated to compensate for this.

Referring to FIG. 4 , the transfer tray 150 may be controlled by the main control unit so that the substrate on which the polarization grid is formed is transferred at an angle of 10 degrees or more and 20 degrees or less with respect to the horizontal axis. Since the angle of incidence (ϕ) of the deposition (coating) material varies in the range of 20 degrees to 40 degrees, it is desirable to compensate for the transfer tray 150 with an inclination of 10 degrees or more and 20 degrees or less.

The thickness of the reflective thin film 104 formed by the polarizing filter manufacturing method using the ion beam sputtering device of the present invention is 0.2 μm or more and 0.5 μm or less, and the thickness of the blackening thin film 105 is 0.2 μm or more and 0.5 μm or less.

The present invention has been described above based on several examples, which are intended to illustrate the present invention. A person skilled in the art would be able to transform or modify the above embodiment into another form while maintaining the technical idea. However, since the scope of rights of this application is determined by the scope of the patent claims below, such variations or modifications may be interpreted as being included in the scope of the rights of the patent claims below.

101: Base substrate 102: Low refractive index material
103: High refractive index material 104: Reflective thin film
105: blackening thin film 106: residual film
110: Sputtering target 120: Focused ion beam generator
130: shutter 140: shielding mask
141: Slit 150: Transfer tray

Claims (5)

Forming an optical layer that is a laminate of a low-refractive material and a high-refractive material on a base substrate;
patterning the optical layer to form a polarization grid;
After inserting the polarization grid into a vacuum chamber in which an ion beam sputtering device is installed, a target is sputtered to form a deposition film on the top of the polarization grid, wherein the ion beam sputtering device includes a linearly focused ion beam generator, and the target rotates. It is a cylindrical target, and the linearly focused ion beam generator generates ions from a neutral gas in a vacuum chamber, focuses them, and makes them incident on the curved side of the cylindrical target as a linearly focused ion beam. The angle of incidence is the length of the side of the cylindrical target. A step of exceeding 70° and below 85° based on a plane perpendicular to the normal direction along the direction; and
A method of manufacturing a polarizing filter using an ion beam sputtering device, comprising: removing a residual film remaining between the polarizing gratings. The method of claim 1, wherein forming the deposition film includes
A method of manufacturing a polarizing filter using an ion beam sputtering device, wherein the deposited film is composed of a reflective thin film, a blackened thin film, or a laminate of the reflective thin film and the blackened thin film. According to claim 1 or 2,
A polarization filter manufacturing method using an ion beam sputtering device, comprising the step of transferring the base substrate on which the polarization grid is formed at an angle of 10 to 20° with respect to the horizontal axis. delete delete

Images