Liquid crystal cells – elements and systems – Particular structure – Having significant detail of cell structure only
Reexamination Certificate
2002-12-12
2004-12-07
Ngo, Huyen (Department: 2871)
Liquid crystal cells, elements and systems
Particular structure
Having significant detail of cell structure only
C349S043000, C349S187000
Reexamination Certificate
active
06829024
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a reflective liquid crystal display and a fabricating method thereof. More particularly, the present invention relates to a reflective liquid crystal display and a method for fabricating the same, which allows a fabricating process to be simple by eliminating a rubbing process as used in the prior method while maintaining an uneven surface design for increasing reflectance during the fabricating process.
2. Description of the Prior Art
A method for fabricating a liquid crystal display according to the prior art will now be described with reference to FIG.
1
.
FIG. 1
is a cross-sectional view for describing a reflective crystal display according to the prior art and a fabricating method thereof, which shows an array substrate structure formed by means of transmissive four masks.
As shown in
FIG. 1
, in fabricating the array substrate structure of the liquid crystal display according to the prior art, a gate
13
is first formed on a transparent substrate
11
by a first mask process. Then, an insulating film
15
made of SiN
x
is formed on the transparent substrate
11
including the gate
13
.
Thereafter, an amorphous silicon layer (not shown), an ohmic layer (not shown) and a conducting layer (not shown) for forming a source/drain region are deposited on the insulating film
15
, and successively patterned by a second mask process to form an amorphous silicon layer pattern
17
, an ohmic layer pattern
19
, a source/drain region
21
and a channel region.
Next, a protective film
23
is deposited on the entire structure and selectively patterned by a third mask process so as to expose the drain
21
.
Then, ITO is deposited on the entire structure including the exposed drain
21
and patterned by a fourth mask process to form a pixel electrode
25
.
In a general liquid crystal display comprising this array substrate structure, liquid crystal molecules are sandwiched between two transparent substrates, and polarizing plates are attached on the outer sides of substrates, reflectively. Thus, the arrangement of the liquid crystal molecules are changed depending on electrical signals inputted to the transparent electrode disposed between the liquid crystal layer and each of the two substrates, such that the polarizing direction of light passed through the polarizing plates can be controlled, and the passage and blocking of light can be controlled.
In a TN mode display among the prior liquid crystal displays, the liquid crystal molecules sandwiched between the upper and lower electrode plates parallel to each other are aligned under application of an electric field. At this time, since there is no compensation effect for the optical anisotropy of liquid crystal molecules, a narrow viewing angle becomes a great problem.
In an attempt to solve this problem of the narrow viewing angle, there was proposed a method in which a WV film as a compensation film is attached. However, this method has the problem of increased costs.
Moreover, in the liquid crystal mode, liquid crystal molecules aligned with respect to the direction of an electrical field is applied. In this case, the alignment degeneracy occurs in which the liquid crystal molecules are aligned in the right and left sides with respect to the electric field.
As a result, a characteristic of slow response time occurs, and disclination lines are produced so as to deteriorate image quality.
To improve these problems, it is a general method to control the alignment of the liquid crystal molecules by an initial rubbing process. However, the rubbing process has problems in that it can cause many factors associated with poor products, including static electricity and dust.
SUMMARY OF THE INVENTION
Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and an object of the present invention is to provide a reflective liquid crystal display and a method of fabricating the same, which allows a fabricating process to be simple by eliminating a rubbing process as used in the prior method while maintaining an uneven surface design for increasing reflectance during the fabricating process.
Another object of the present invention is to a reflective liquid crystal display device and a method of fabricating the same, which permits omitting the rubbing process so that the alignment degeneracy of liquid crystal molecules is prevented, contrast ratio is increased, and viewing angle, luminance and response time are improved.
To achieve the above objects, in one aspect, the present invention provides a reflective liquid crystal display which comprises a gate formed on a transparent substrate, an insulating film formed on a transparent electrode including the gate, and an amorphous silicon layer pattern, an ohmic layer pattern and a source/drain region deposited on the insulating film, the reflective liquid crystal display further comprising a resin layer which is formed on the entire structure including the source/drain region, in such a manner that the drain region is partially exposed; a first reflective electrode formed on the resin layer including the drain region, and a second reflective electrode of an uneven shape formed on the first reflective electrode.
In another aspect, the present invention provides a method of fabricating a reflective liquid crystal display comprising the steps of: forming a gate on a transparent insulating substrate; forming an insulating film on a transparent electrode including the gate; and forming an amorphous silicon layer pattern, an ohmic layer pattern and a source/drain region on the insulating film, the method further comprising the steps of: forming a resin layer on the entire structure including the source/drain region; forming a contact hole in the resin layer in such a manner that the drain region is exposed through the contact hole; forming a first reflective electrode on the resin layer including the drain region; and forming a second reflective electrode of an uneven shape on the first reflective electrode.
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Koh Jai Wan
Park Young Il
Suh Dong Hae
Boe-Hydis Technology Co., Ltd.
Ladas & Parry LLP
Ngo Huyen
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