KR20040033416A - Method of manufacturing semitransmission type liquid crystal display - Google Patents

Abstract

PURPOSE: A method for manufacturing a transflective liquid crystal display is provided to form a transmissive plate without using an extra mask, thereby improving the productivity. CONSTITUTION: A transparent insulating substrate(301) which is divided into a transmissive area and a reflective area is provided. TFT(Thin Film Transistor)s(313) are formed on the substrate. A passivation film is formed on the whole area of the substrate to cover the TFTs. First via holes are formed by etching the passivation film to expose electrodes of the TFTs. A resin film(319) is applied on the substrate. Second via holes are formed by etching the resin film, and aperture parts are formed on the transmissive area. First and second metal films are deposited on the second via holes, the resin film, and the aperture parts. A buffer film(325) and a reflective plate(323) are formed by removing the first and second metal films formed on the aperture parts. A transparent metal film is deposited on the substrate. A photo sensitive film is applied on the transparent metal film. The photo sensitive film is exposed and developed to remove the photo sensitive film applied on the buffer layer and form photo sensitive film patterns on the transparent metal film on the aperture parts. The transparent metal film deposited on the reflective area is etched by using the photo sensitive film pattern as an etching wall, and a transmissive plate(330) is formed on the aperture parts at the same time. The photo sensitive film patterns are removed. The buffer film formed on the reflective plate is removed.

Description

Method of manufacturing semi-transmissive liquid crystal display device {Method of manufacturing semitransmission type liquid crystal display}

The present invention relates to a method of manufacturing a transflective liquid crystal display device, and more particularly, to a method of manufacturing a transflective liquid crystal display device having a reduced number of mask processes.

The liquid crystal display may be classified into two types, a transmissive liquid crystal display using a backlight as a light source and a reflective liquid crystal display using a light source of natural light.

Since the transmissive liquid crystal display uses a backlight as a light source, it realizes a bright image even in a dark environment, but has a problem in that power consumption is increased by using the backlight. On the other hand, the reflective liquid crystal display device does not use a backlight, but the power consumption is small, but there is a problem that can not be used when the surrounding environment is dark.

The semi-transmissive liquid crystal display device proposed to solve the above problems is, because it is possible to use both the reflection type and the transmissive type as needed, it can be used in a dark environment with a relatively low power consumption.

FIG. 1 is a plan view illustrating a conventional transflective liquid crystal display device. As shown in FIG. 1, the transflective liquid crystal display device reflects incident light when the ambient light is bright enough to enable a display function without using a backlight. And the light is reflected by the liquid crystal display device, and when the ambient light is not bright, the backlight is used to enter the liquid crystal layer through the opening 20 of the reflector using the backlight to operate as a transmissive liquid crystal display device. Here, reference numeral 30, which is not described, is a via hole.

2A to 2D are cross-sectional views illustrating processes for manufacturing an array substrate of a transflective liquid crystal display device according to the prior art.

Referring to FIG. 2A, a TFT 213 is formed in place of a transparent insulating substrate 201 such as a glass substrate partitioned into a transmission region and a reflection region. The TFT 213 may include a gate electrode 203, a gate insulating film 205 covering the substrate 201 including the gate electrode 203, and a gate insulating film 205 on the gate electrode 203. And a channel layer 207 and an ohmic layer 211 stacked thereon, and source and drain electrodes 209a and 209b formed on the ohmic layer 211.

Subsequently, a first via hole exposing the source electrode 209a of the TFT 213 by depositing a passivation layer 215 for protecting the TFT 213 on the substrate resultant and etching a predetermined portion of the passivation layer 215. 217a is formed.

Referring to FIG. 2B, a source film of the TFT 213 is applied through the first via hole 217a by applying a resin film 219 on the passivation layer 215, etching certain portions of the resin film 219. A second via hole 217b exposing 209a is formed, and an opening 221 is formed in the resin film on the transmission region of the substrate 201. Subsequently, although not shown, an embossing (not shown) is formed on the surface of the portion of the resin film 219 in the reflective region of the substrate to improve luminance.

Referring to FIG. 2C, an AlNd film and a Mo film are sequentially deposited on the surface of the opening 221, the resin film 219, and the second via hole 217b as a reflector metal film and a buffer film. Then, the Mo film and the AlNd film deposited on the surface of the opening 221 are removed through a mask process, and through this, the buffer film 225 and the reflecting plate 223 are formed on the resin film on the substrate reflection area.

Referring to FIG. 2D, a transparent metal film is deposited on the substrate resultant, and then a transparent plate 227 is formed on the surface of the opening 221 of the substrate transmission region through a mask process with respect to the transparent metal film.

Subsequently, although not shown, the buffer film remaining on the reflector is removed.

However, according to the conventional method of manufacturing an array substrate of a transflective liquid crystal display device, since both the process of forming the reflecting plate and the process of forming the transmissive plate perform a mask process, two mask processes must be performed and each mask is manufactured. Since there is a need for this, there is a problem in that productivity decreases as the manufacturing cost increases.

Accordingly, an object of the present invention is to provide a method for manufacturing a transflective liquid crystal display device which can prevent a decrease in productivity.

1 is a plan view showing a conventional transflective liquid crystal display device

2A to 2D are cross-sectional views of processes for explaining a method of manufacturing a transflective liquid crystal display device according to the related art.

3A to 3D are cross-sectional views of processes for explaining a method of manufacturing a transflective liquid crystal display according to an exemplary embodiment of the present invention.

Explanation of symbols on main parts of drawing

301: insulating substrate 303: gate electrode

305: gate insulating film 307: channel layer

309a: source electrode 309b: drain electrode

311: ohmic layer 313: TFT

315: first protective film 317: first via hole

317b: Second Via Hole 319: Resin Film

321: opening 323: reflector

325: buffer layer 327: transparent electrode

329 photosensitive film 329a photosensitive film pattern

330: transmission plate

In order to achieve the above object, the present invention provides a transparent insulating substrate partitioned into a transmission region and a reflection region; Forming a TFT in place of the substrate; Forming a protective film over the entire area of the substrate so as to cover the TFT; Etching the passivation layer to form a first via hole exposing the electrode of the TFT; Applying a resin film on the substrate resultant; Etching the resin film to form a second via hole for exposing the electrode of the TFT and forming an opening in a substrate transmission area; Sequentially depositing a first metal film and a second metal film on the second via hole surface, the resin film, and the opening surface; Removing the second metal film and the first metal film on the surface of the opening to form a buffer film and a reflector on a portion of the resin film on the substrate reflection area; Depositing a transparent metal film on the substrate resultant; Applying a photosensitive film on the transparent metal film such that the thickness of the openings is relatively thick; Exposing and developing the photoresist to a full surface to remove the photoresist applied on the buffer film on the substrate reflection area and to form a photoresist pattern on the transparent metal film portion on the opening; Using the photoresist pattern as an etch barrier to etch a portion of the transparent metal film on the reflective region of the substrate and to form a transmissive plate on the surface of the opening; Removing the photoresist pattern; And it is an object of the present invention to provide a method of manufacturing a transflective liquid crystal display device comprising the step of removing the buffer film formed on the reflective plate.

Here, the opening of the transmissive region of the substrate has a height of 2 μm or more and a short axis of 50 μm or less in order to give a step in subsequent application of the photosensitive film. Further, the photosensitive film has a thickness of 2 μm or less on the buffer film of the reflective region of the substrate.

The first metal film is made of AlNd and the second metal film is made of Mo.

According to the present invention, after applying a photosensitive film having a step on the transparent electrode, it is exposed and developed to remove a portion having a low step, thereby leaving a portion of the photosensitive film having a high step to form a photosensitive film pattern. By using the photoresist pattern as an etch barrier, the transparent electrode is patterned to form a transmissive plate in the transmissive region of the substrate, thus eliminating the need for a separate mask for forming the transmissive plate.

(Example)

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

3A to 3F are cross-sectional views illustrating processes of manufacturing an array substrate of a transflective liquid crystal display according to an exemplary embodiment of the present invention.

Referring to FIG. 3A, a TFT 313 is formed in place of a transparent insulating substrate 301 such as a glass substrate partitioned into a transmission region and a reflection region. Here, the TFT 313 includes a gate electrode 303, a gate insulating film 305 covering the substrate 301 including the gate electrode 303, and a gate insulating film 305 on the gate electrode 303. And a channel layer 307 and an ohmic layer 311 stacked on the source layer and source and drain electrodes 309a and 309b formed on the ohmic layer 311.

Subsequently, a first via hole exposing the source electrode 309a of the TFT 313 by depositing a passivation layer 315 to protect the TFT 313 on the substrate resultant and etching a predetermined portion of the passivation layer 315. 317a is formed.

Referring to FIG. 3B, a second via hole 317b exposing the source electrode 309a of the TFT 313 is formed by applying a resin film 319 on the passivation layer 315 and etching predetermined portions thereof. An opening 321 is formed in a portion of the resin film 319 on the substrate transmission region. Here, although not exactly illustrated, the opening 321 has a height of 2 μm or more to give a difference in thickness during subsequent photosensitive film deposition. It is formed to have a width of 50㎛ or less.

In addition, an embossing (not shown) is formed on the surface of the portion of the resin film 319 on the substrate reflection area to improve luminance.

Referring to FIG. 3C, an AlNd film and an Mo film are sequentially deposited on the surface of the opening 321, the resin film 319, and the second via hole 317b as a metal film and a buffer film for reflecting plates. Then, the AlNd film and the Mo film are etched to remove the Mo film and the AlNd film formed on the surface of the opening 321, thereby forming the buffer film 325 and the reflector 323 on the resin film portion of the substrate reflective region. Form.

Referring to FIG. 3D, a transparent metal film 327 is deposited on the substrate resultant 321. Then, a photosensitive film 329 is coated on the transparent metal film 327. In this case, the photosensitive film 329 is applied to a relatively thick thickness on the opening 321 of the substrate transmission region, while the photosensitive film 329 is applied to the buffer film on the reflective plate 323 with a significantly thinner thickness than 2㎛.

Referring to FIG. 3E, the entire surface is exposed and developed at an appropriate exposure amount on the substrate resultant to remove a portion of the photoresist applied on the transparent metal film 327 on the substrate reflection area. At this time, the photoresist pattern 329a remains on the opening 321 of the substrate transmission region in relation to the application of the photoresist in a relatively thick manner.

Referring to FIG. 3F, the transparent electrode deposited on the buffer layer 325 on the substrate reflection region is removed using the photoresist pattern 329a as an etch barrier, and then the opening is formed by removing the photoresist pattern 329a. The transmission plate 330 is formed on the surface 321.

Thereafter, although not shown, the buffer film remaining on the reflector is removed.

As described above, since the method of the present invention does not implement a separate mask when forming the transmission plate, it is possible to reduce the manufacturing cost than conventional. That is, after applying a photosensitive film having a step on the transparent electrode, it is exposed and developed to remove a portion having a low step, thereby leaving a portion of the photosensitive film having a high step to form a photosensitive film pattern, and subsequently The transparent electrode is patterned using an etch barrier to form a transmissive plate in the transmissive region of the substrate, thus eliminating the need for a separate mask for forming the transmissive plate.

As described above, the present invention does not require a separate mask when forming the transmission plate, it is possible to reduce the production cost according to the use of the mask, thereby improving the productivity.

In addition, this invention can be implemented in various changes in the range which does not deviate from the summary.

Claims (2)

Providing a transparent insulating substrate partitioned into transmissive and reflective regions; Forming a TFT in place of the substrate; Forming a protective film over the entire area of the substrate so as to cover the TFT; Etching the passivation layer to form a first via hole exposing the electrode of the TFT; Applying a resin film on the substrate resultant; Etching the resin film to form a second via hole for exposing the electrode of the TFT and forming an opening in a substrate transmission area; Sequentially depositing a first metal film and a second metal film on the second via hole surface, the resin film, and the opening surface; Removing the second metal film and the first metal film on the surface of the opening to form a buffer film and a reflector on a portion of the resin film on the substrate reflection area; Depositing a transparent metal film on the substrate resultant; Applying a photosensitive film on the transparent metal film such that the thickness of the openings is relatively thick; Exposing and developing the photoresist to a full surface to remove the photoresist applied on the buffer film on the substrate reflection area and to form a photoresist pattern on the transparent metal film portion on the opening; Using the photoresist pattern as an etch barrier to etch a portion of the transparent metal film on the reflective region of the substrate and to form a transmissive plate on the surface of the opening; Removing the photoresist pattern; And And removing the buffer film formed on the reflective plate. The method of claim 1, wherein the opening is formed to have a height of 2 µm or more and a width of 50 µm or less.