U.S. patent application number 14/990946 was filed with the patent office on 2016-05-05 for liquid crystal display and manufacturing method thereof.
The applicant listed for this patent is Samsung Display Co., Ltd.. Invention is credited to Kyung Tae CHAE, Jun Heui LEE, Seon Uk LEE, Tae Woo LIM, Sung Hwan WON.
Application Number | 20160124261 14/990946 |
Document ID | / |
Family ID | 51525819 |
Filed Date | 2016-05-05 |
United States Patent
Application |
20160124261 |
Kind Code |
A1 |
LIM; Tae Woo ; et
al. |
May 5, 2016 |
LIQUID CRYSTAL DISPLAY AND MANUFACTURING METHOD THEREOF
Abstract
A manufacturing method of a liquid crystal display includes:
providing a pixel electrode on an insulation substrate; providing a
sacrificial layer on the pixel electrode; providing a common
electrode on the sacrificial layer; providing a photoresist layer
on the common electrode; exposing a portion of the photoresist
layer, common electrode and the sacrificial layer with light;
developing the portion of the photoresist layer exposed with the
light; etching a layer between the photoresist layer and the
sacrificial layer using the developed photoresist layer as a mask
to expose the portion of the sacrificial layer exposed with the
light; removing the portion of the sacrificial layer exposed with
the light; providing a roof layer on the insulation substrate and
etching the roof layer to form a liquid crystal injection hole
therein; and removing the sacrificial layer exposed through the
liquid crystal injection hole to form a microcavity.
Inventors: |
LIM; Tae Woo; (Hwaseong-si,
KR) ; CHAE; Kyung Tae; (Hwaseong-si, KR) ;
WON; Sung Hwan; (Suwon-si, KR) ; LEE; Seon Uk;
(Seongnam-si, KR) ; LEE; Jun Heui; (Seoul,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Samsung Display Co., Ltd. |
Yongin-City |
|
KR |
|
|
Family ID: |
51525819 |
Appl. No.: |
14/990946 |
Filed: |
January 8, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14209263 |
Mar 13, 2014 |
9268164 |
|
|
14990946 |
|
|
|
|
Current U.S.
Class: |
349/138 |
Current CPC
Class: |
G02F 1/134309 20130101;
G02F 1/133377 20130101; G02F 1/1341 20130101; G02F 1/133345
20130101; G02F 2001/134318 20130101 |
International
Class: |
G02F 1/1333 20060101
G02F001/1333; G02F 1/1343 20060101 G02F001/1343; G02F 1/1341
20060101 G02F001/1341 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 13, 2013 |
KR |
10-2013-0026848 |
Claims
1. A liquid crystal display comprising: an insulation substrate; a
pixel electrode disposed on the insulation substrate; a plurality
of microcavities defined on the pixel electrode; a plurality of
common electrodes disposed on the microcavities, respectively; a
roof layer which covers the common electrodes and the microcavities
and comprises a column portion; and a liquid crystal layer disposed
in the microcavities, wherein adjacent microcavities are connected
to each other.
2. The liquid crystal display of claim 1, wherein the column
portion of the roof layer extends substantially in a first
direction and is disposed between the microcavities, and an empty
space is defined in the column portion, and the microcavities are
connected through the empty space in the column portion.
3. The liquid crystal display of claim 2, wherein a liquid crystal
injection hole is defined between the microcavities adjacent to
each other in the first direction, and the liquid crystal injection
hole is exposed by the roof layer.
4. The liquid crystal display of claim 2, wherein the common
electrodes adjacent to each other in a second direction, which is
substantially perpendicular to the first direction, are connected
to each other through the empty space in the column portion of the
roof layer.
5. The liquid crystal display of claim 4, further comprising: a
lower insulating layer disposed between the roof layer and the
common electrodes.
6. The liquid crystal display of claim 5, wherein the lower
insulating layer has a pattern corresponding to the common
electrodes.
7. The liquid crystal display of claim 5, further comprising: an
additional lower insulating layer disposed between the lower
insulating layer and the roof layer.
8. The liquid crystal display of claim 4, further comprising: an
upper insulating layer which encloses upper and side surfaces of
the roof layer.
Description
[0001] This application is a divisional of U.S. patent application
Ser. No. 14/209,263, filed on Mar. 13, 2014, which claims priority
to Korean Patent Application No. 10-2013-0026848 filed on Mar. 13,
2013, and all the benefits accruing therefrom under 35 U.S.C.
.sctn.119, the content of which in its entirety is herein
incorporated by reference.
BACKGROUND
[0002] (a) Field
[0003] The invention relates to a liquid crystal display and a
manufacturing method of the liquid crystal display, and more
particularly, to a liquid crystal display having a liquid crystal
layer in a microcavity, and a manufacturing method of the liquid
crystal display.
[0004] (b) Description of the Related Art
[0005] A liquid crystal display, which is one of the most widely
used type of flat panel display device, typically includes two
display panels where field generating electrodes such as a pixel
electrode and a common electrode are provided, and a liquid crystal
layer interposed between the two display panels.
[0006] The liquid crystal display generates an electric field in
the liquid crystal layer by applying voltages to the field
generating electrodes to determine orientations of liquid crystal
molecules of the liquid crystal layer and control polarization of
incident light, thereby displaying an image.
[0007] A liquid crystal display having an embedded microcavity
("EM") structure (e.g., nanocrystal structure) is a display device
manufactured by providing a sacrificial layer with a photoresist,
removing the sacrificial layer after coating a support member
thereon, and filling a liquid crystal in an empty space provided by
removing the sacrificial layer.
[0008] In such a liquid crystal display, when developing the
sacrificial layer or performing a heat treatment for an overlying
layer, a characteristic thereof may be changed such that the
sacrificial layer may partially remain in the space to be filled by
the liquid crystal when removing the sacrificial layer. Also, the
common electrode may have a curved structure according to the
sacrificial layer such that the common electrode may be disposed
substantially close to the underlying pixel electrode.
SUMMARY
[0009] Exemplary embodiments of the invention relate to a liquid
crystal display including a microcavity having a substantially
uniform cell gap and a manufacturing method of the liquid crystal
display. Exemplary embodiments of the invention relate to a liquid
crystal display, in which a common electrode and a pixel electrode
have a substantially uniform distance therebetween, and a
manufacturing method of the liquid crystal display.
[0010] An exemplary embodiment of a manufacturing method of a
liquid crystal display according to the invention includes:
providing a pixel electrode on an insulation substrate; providing a
sacrificial layer on the pixel electrode; providing a common
electrode on the sacrificial layer; providing a photoresist layer
on the common electrode; exposing a portion of the photoresist
layer, common electrode and the sacrificial layer with light;
developing the portion of the photoresist layer exposed with the
light; etching a layer between the photoresist layer and the
sacrificial layer using the developed photoresist layer as a mask
to expose the portion of the sacrificial layer exposed with the
light; removing the portion of the sacrificial layer exposed with
the light; providing a roof layer on the insulation substrate and
etching the roof layer to form a liquid crystal injection hole
therein; and removing the sacrificial layer exposed through the
liquid crystal injection hole to form a microcavity.
[0011] In an exemplary embodiment, the method may further includes
providing a lower insulating layer between the common electrode and
the photoresist layer, where the sacrificial layer, the common
electrode and the photoresist layer cover the pixel electrode on
the substrate.
[0012] In an exemplary embodiment, the portion of the sacrificial
layer exposed with the light may correspond to the liquid crystal
injection hole and a column portion of the roof layer.
[0013] In an exemplary embodiment, the etching the layer between
the photoresist layer and the sacrificial layer using the developed
photoresist layer as a mask may include: etching the lower
insulating layer using the developed photoresist layer as a mask;
removing the photoresist layer; and etching the common electrode
using the etched lower insulating layer as a mask to expose the
portion of the sacrificial layer exposed with the light.
[0014] In an exemplary embodiment, the method may further include
providing an additional lower insulating layer on the substrate,
before the providing the roof layer on the substrate and the
etching the roof layer to form the liquid crystal injection hole
therein and after removing the portion of the sacrificial layer
exposed with the light.
[0015] In an exemplary embodiment, the providing the roof layer on
the substrate and the etching the roof layer to form the liquid
crystal injection hole therein may include: the providing the roof
layer on the substrate; exposing a portion of the provided roof
layer corresponding to the removed portion of the sacrificial layer
with light; developing the portion of the roof layer exposed with
the light; providing an upper insulating layer on the substrate to
cover the developed roof layer; and removing a portion of the upper
insulating layer corresponding to the removed portion of the
sacrificial layer to form the liquid crystal injection hole.
[0016] In an exemplary embodiment, the etching the layer between
the photoresist layer and the sacrificial layer using the developed
photoresist layer as a mask may include: etching the common
electrode using the developed photoresist layer as a mask to expose
the portion of the sacrificial layer exposed with the light; and
removing the photoresist layer.
[0017] In an exemplary embodiment, the removing the photoresist
layer may include using an ashing process, and the exposed portion
of the sacrificial layer may be partially removed by the ashing
process.
[0018] In an exemplary embodiment, the removed portion of the
sacrificial layer by the ashing process may be positioned under the
common electrode.
[0019] In an exemplary embodiment, the method may further include
providing an additional lower insulating layer on the substrate,
before the providing the roof layer on the substrate and the
etching the roof layer to form the liquid crystal injection hole
therein and after the removing the portion of the sacrificial layer
exposed with the light.
[0020] In an exemplary embodiment, the providing the roof layer on
the substrate and the etching the roof layer to form the liquid
crystal injection hole therein may include: the providing the roof
layer on the substrate; exposing a portion of the provided roof
layer corresponding to the removed portion of the sacrificial layer
with light; developing the portion of the roof layer with the
light; providing an upper insulating layer on the substrate to
cover the developed roof layer; and removing a portion of the upper
insulating layer corresponding to the removed portion of the
sacrificial layer to form the liquid crystal injection hole.
[0021] In an exemplary embodiment, the exposed portion of the
sacrificial layer may correspond to the liquid crystal injection
hole and a column portion of the roof layer.
[0022] An exemplary embodiment of a liquid crystal display
according to the invention includes: an insulation substrate; a
pixel electrode disposed on the insulation substrate; a plurality
of microcavities defined on the pixel electrode; a plurality of
common electrodes disposed on the microcavities, respectively; a
roof layer which covers the common electrodes and the microcavities
and includes a column portion; and a liquid crystal layer disposed
in the microcavity, where adjacent microcavities are connected to
each other.
[0023] In an exemplary embodiment, the column portion of the roof
layer may extend substantially in a first direction and may be
disposed between the microcavities, and an empty space may be
defined in the column portion, and the microcavities may be
connected through the empty space in the column portion.
[0024] In an exemplary embodiment, a liquid crystal injection hole
may be defined between the microcavities adjacent to each other in
the first direction, and the liquid crystal injection hole may be
exposed by the roof layer.
[0025] In an exemplary embodiment, the common electrodes adjacent
to each other in a second direction, which is substantially
perpendicular to the first direction, may be connected to each
other through the empty space in the column portion of the roof
layer.
[0026] In an exemplary embodiment, the liquid crystal display may
further include a lower insulating layer disposed between the roof
layer and the common electrode.
[0027] In an exemplary embodiment, the lower insulating layer may
have a pattern corresponding to the common electrodes.
[0028] In an exemplary embodiment, the liquid crystal display may
further include an additional lower insulating layer disposed
between the lower insulating layer and the roof layer.
[0029] In an exemplary embodiment, the liquid crystal display may
further include an upper insulating layer which encloses upper and
side surfaces of the roof layer.
[0030] In exemplary embodiments, the influence of the developing
treatment or the heat treatment is not performed before removing
the sacrificial layer such that the sacrificial layer is
substantially entirely removed during a process for removing the
sacrificial layer, and the cell gap of the microcavity is thereby
substantially uniformly maintained. In such exemplary embodiments,
the common electrode is provided only on the microcavity and spaced
apart from the pixel electrode at a predetermined distance such
that a short circuit between the common electrode and the pixel
electrode is effectively prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The above and other features of the invention will become
more apparent by describing in further detail exemplary embodiments
thereof with reference to the accompanying drawings, in which:
[0032] FIG. 1 is a top plan view of pixels of an exemplary
embodiment of a liquid crystal display according to the
invention;
[0033] FIG. 2 is a top plan view of a portion of the pixels of FIG.
1;
[0034] FIG. 3 is a cross-sectional view taken along line A-B of
FIG. 1 and FIG. 2;
[0035] FIG. 4 is a cross-sectional view taken along line C-D of
FIG. 1 and FIG. 2;
[0036] FIG. 5 to FIG. 16 are cross-sectional views taken along a
line corresponding to line E-F of FIG. 1, sequentially showing an
exemplary embodiment of a manufacturing method of a liquid crystal
display according to an exemplary embodiment of FIG. 1 taken along
the line E-F;
[0037] FIG. 17 and FIG. 18 are cross-sectional views taken along al
line corresponding to line C-D of FIG. 1, sequentially showing an
exemplary embodiment of a manufacturing method of a liquid crystal
display according to the invention;
[0038] FIG. 19 to FIG. 21 are cross-sectional views sequentially
showing an alternative exemplary embodiment of a manufacturing
method of a liquid crystal display according the invention;
[0039] FIG. 22 to FIG. 33 are cross-sectional views sequentially
showing an alternative exemplary embodiment of a manufacturing
method of a liquid crystal display according to the invention;
[0040] FIG. 34 to FIG. 36 are cross-sectional views sequentially
showing an alternative exemplary embodiment of a manufacturing
method of a liquid crystal display according to the invention;
and
[0041] FIG. 37 is a top plan view of a pixel of a liquid crystal
display according to an exemplary embodiment of the invention.
DETAILED DESCRIPTION
[0042] The invention will be described more fully hereinafter with
reference to the accompanying drawings, in which exemplary
embodiments of the invention are shown. This invention may,
however, be embodied in many different forms, and should not be
construed as limited to the embodiments set forth herein. Rather,
these embodiments are provided so that this disclosure will be
thorough and complete, and will fully convey the scope of the
invention to those skilled in the art. Like reference numerals
refer to like elements throughout.
[0043] It will be understood that when an element or layer is
referred to as being "on," "connected to" or "coupled to" another
element or layer, the element or layer can be directly on,
connected or coupled to the other element or layer or intervening
elements or layers may be present. In contrast, when an element is
referred to as being "directly on," "directly connected to" or
"directly coupled to" another element or layer, there are no
intervening elements or layers present. Like numbers refer to like
elements throughout. As used herein, the term "and/or" includes any
and all combinations of one or more of the associated listed
items.
[0044] It will be understood that, although the terms first,
second, third, etc., may be used herein to describe various
elements, components, regions, layers and/or sections, these
elements, components, regions, layers and/or sections should not be
limited by these terms. These terms are only used to distinguish
one element, component, region, layer or section from another
region, layer or section. Thus, a first element, component, region,
layer or section discussed below could be termed a second element,
component, region, layer or section without departing from the
teachings of the invention.
[0045] Spatially relative terms, such as "beneath", "below",
"lower", "above", "upper" and the like, may be used herein for ease
of description to describe one element or feature's relationship to
another element(s) or feature(s) as illustrated in the figures. It
will be understood that the spatially relative terms are intended
to encompass different orientations of the device in use or
operation, in addition to the orientation depicted in the figures.
For example, if the device in the figures is turned over, elements
described as "below" or "beneath" other elements or features would
then be oriented "above" the other elements or features. Thus, the
exemplary term "below" can encompass both an orientation of above
and below. The device may be otherwise oriented (rotated 90 degrees
or at other orientations) and the spatially relative descriptors
used herein interpreted accordingly.
[0046] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the invention. As used herein, the singular forms "a," "an" and
"the" are intended to include the plural forms as well, unless the
context clearly indicates otherwise. It will be further understood
that the terms "includes" and/or "including," when used in this
specification, specify the presence of stated features, integers,
steps, operations, elements, and/or components, but do not preclude
the presence or addition of one or more other features, integers,
steps, operations, elements, components, and/or groups thereof.
[0047] Unless otherwise defined, all terms (including technical and
scientific terms) used herein have the same meaning as commonly
understood by one of ordinary skill in the art to which this
invention belongs. It will be further understood that terms, such
as those defined in commonly used dictionaries, should be
interpreted as having a meaning that is consistent with their
meaning in the context of the relevant art and will not be
interpreted in an idealized or overly formal sense unless expressly
so defined herein.
[0048] Embodiments of the invention are described herein with
reference to cross-section illustrations that are schematic
illustrations of idealized embodiments (and intermediate
structures) of the invention. As such, variations from the shapes
of the illustrations as a result, for example, of manufacturing
techniques and/or tolerances, are to be expected. Thus, embodiments
of the invention should not be construed as limited to the
particular shapes of regions illustrated herein but are to include
deviations in shapes that result, for example, from manufacturing.
For example, a region illustrated or described as flat may,
typically, have rough and/or nonlinear features. Moreover, sharp
angles that are illustrated may be rounded. Thus, the regions
illustrated in the figures are schematic in nature and their shapes
are not intended to illustrate the precise shape of a region and
are not intended to limit the scope of the claims set forth
herein.
[0049] All methods described herein can be performed in a suitable
order unless otherwise indicated herein or otherwise clearly
contradicted by context. The use of any and all examples, or
exemplary language (e.g., "such as"), is intended merely to better
illustrate the invention and does not pose a limitation on the
scope of the invention unless otherwise claimed. No language in the
specification should be construed as indicating any non-claimed
element as essential to the practice of the invention as used
herein.
[0050] Hereinafter, exemplary embodiments of the invention will be
described in further detail with reference to the accompanying
drawings.
[0051] Now, an exemplary embodiment of a liquid crystal display
according to the invention will be described with reference to FIG.
1 to FIG. 4.
[0052] FIG. 1 is a top plan view of pixels in an exemplary
embodiment of a liquid crystal display according to the invention
in a view top, FIG. 2 is a top plan view of a portion of the pixels
of FIG. 1, FIG. 3 is a cross-sectional view taken along line A-B of
FIG. 1 and FIG. 2, and FIG. 4 is a cross-sectional view taken along
line C-D of FIG. 1 and FIG. 2.
[0053] In an exemplary embodiment of a liquid crystal display
according to the invention, a liquid crystal layer is disposed in a
microcavity 305 on an insulation substrate, and an opposing
substrate is omitted. Hereinafter, a microcavity and a structure
thereof in an exemplary embodiment will be described in detail, and
structures of wiring under the microcavity and electrodes in such
an embodiment is not limited to a specific structures, but may have
various structures.
[0054] FIG. 1 and FIG. 2 are top plan views showing the pixels in
an exemplary embodiment of the liquid crystal display, and the
structure of the wiring and the electrode are not shown therein.
The structure of the wiring and the electrode in the pixels may be
various, and the structure of the wiring and the electrode in an
exemplary embodiment will be described later in detail with
reference to FIG. 37.
[0055] Now, a pixel electrode 191, the microcavity 305 and
overlying layers will be described.
[0056] In an exemplary embodiment, the microcavity 305 is supported
by a roof layer 360. The roof layer 360 includes a portion
positioned on the microcavity 305 and a column portion positioned
at a side of the microcavity 305. In FIG. 1 and FIG. 2, the column
portion of the roof layer 360 is indicated by a quadrangular solid
line. Also, an empty portion 305-1 in the column portion of the
roof layer 360 indicated by a dotted line in FIG. 1 is a portion
where the column portion of the roof layer 360 is removed. The
microcavity 305 is defined between adjacent column portions of the
roof layer 360.
[0057] The roof layer 360 is divided into a lower portion and an
upper portion with reference to a liquid crystal injection hole
307. A pixel may be defined by adjacent microcavities 305 in a
first direction (e.g., a y-direction) and positioned upwardly and
downwardly with respect to the liquid crystal injection hole 307,
respectively, or may be defined by a single microcavity 305.
[0058] The microcavity 305 positioned upwardly or downwardly with
respect to the liquid crystal injection hole 307 is connected to
microcavities 305 disposed adjacent thereto in the second
direction, e.g., the x-direction. Referring to FIG. 1 and FIG. 2 as
well as FIG. 4 which is a cross-sectional view taken line C-D of
FIG. 1 and FIG. 2, the microcavities 305 disposed adjacent to each
other in the x-direction are connected by the empty portion 305-1
in the column portion of the roof layer 360. In an exemplary
embodiment, a common electrode 270 is connected to each other in
the x-direction through an upper portion of the empty portion 305-1
in the column portion of the roof layer 360. The empty portion
305-1 in the column portion of the roof layer 360 between adjacent
microcavities 305 is also referred to as a connection 305-1 of the
adjacent microcavities 305.
[0059] In an exemplary embodiment, a thin film transistor of the
pixel may be disposed in a region where the liquid crystal
injection hole 307 is defined.
[0060] FIG. 2 shows the microcavity 305 positioned at one side of
the liquid crystal injection hole 307 in FIG. 1. The
cross-sectional view taken line A-B of FIG. 2 is shown in FIG. 3,
and the cross-sectional view taken line C-D of FIG. 2 is shown in
FIG. 4.
[0061] Referring to FIG. 2 to FIG. 4, an upper structure of the
pixel electrode 191 in the pixel of an exemplary embodiment will be
described.
[0062] In an exemplary embodiment, a passivation layer (not shown)
is disposed on the thin film transistor (not shown) and the wiring
(not shown) on a substrate (not shown), and the pixel electrode 191
is disposed on the passivation layer. The pixel electrode 191 may
include a transparent conductive material such as indium tin oxide
("ITO") or indium zinc oxide ("IZO"), for example. The pixel
electrode 191 receives a data voltage from the thin film transistor
through a contact hole.
[0063] The microcavity 305 is defined on the passivation layer and
the pixel electrode 191. The liquid crystal layer including liquid
crystal molecules 310 is disposed in the microcavity 305.
[0064] An upper surface of the microcavity 305 is substantially
horizontal with respect to the substrate, and a side surface of the
microcavity 305 is tapered. The microcavity 305 is a space provided
by removing a sacrificial layer during a manufacturing process, and
the common electrode 270 and a lower insulating layer 350 are
disposed on the microcavity 305. In an exemplary embodiment, as
shown in FIG. 3, the common electrode 270 may be disposed only at
the upper surface of the microcavity 305.
[0065] In such an embodiment, as described above, the pixel
electrode 191 and the passivation layer are positioned under the
microcavity 305. The column portion of the roof layer 360 is
positioned at the side surface of the microcavity 305. In such an
embodiment, the microcavity 305 is the space defined by the common
electrode 270, the pixel electrode 191, the passivation layer and
the column portion of the roof layer 360.
[0066] The liquid crystal layer is disposed inside the microcavity
305, and an alignment layer (not shown) may be provided inside the
microcavity 305 to arrange the liquid crystal molecules 310 of the
liquid crystal layer in the microcavity 305. The alignment layer as
a liquid crystal alignment layer may include a material such as
polyamic acid, polysiloxane, or polyimide, for example.
[0067] The liquid crystal layer is disposed inside the microcavity
305 (e.g., in the alignment layer in the microcavity 305). The
liquid crystal molecules 310 are initially arranged by the
alignment layer, and an arrangement direction of the liquid crystal
molecules 310 is changed by an electric field generated therein. A
height of the liquid crystal layer corresponds to a height of the
microcavity 305. The liquid crystal layer in the microcavity 305 is
also referred to as a nanocrystal layer.
[0068] In an exemplary embodiment, the liquid crystal layer in the
microcavity 305 may be provided, e.g., inserted, into the
microcavity 305 using capillary force, and the alignment layer may
be provided using the capillary force.
[0069] In the column portion of the roof layer 360 positioned
between the adjacent microcavities 305, as shown in FIG. 4, the
empty portion 305-1 is defined. In such an embodiment, the adjacent
microcavities 305, the common electrode 270 and the lower
insulating layer 350 on the microcavity 305 are connected to each
other through the empty portion 305-1.
[0070] The common electrode 270 is disposed on the microcavity 305.
The common electrode 270 is positioned at the upper surface of the
microcavity 305 and is also disposed on the empty portion 305-1 in
the column portion of the roof layer 360. In such an embodiment,
adjacent common electrodes 270 are spaced apart from each other
with respect to the liquid crystal injection hole 307. The common
electrode 270 may include the transparent conductive material such
as ITO or IZO, for example, and generates an electric field along
with the pixel electrode 191, thereby controlling the arrangement
direction of the liquid crystal molecules 310.
[0071] The lower insulating layer 350 is disposed on the common
electrode 270. The lower insulating layer 350 may include an
inorganic insulating material such as silicon nitride (SiNx),
silicon oxide (SiOx) and silicon oxynitride (SiOxNy), for example.
The lower insulating layer 350 is disposed only on the common
electrode 270, thereby having substantially the same planar shape
as the common electrode 270. In an exemplary embodiment, the lower
insulating layer 350 may have an edge disposed along an edge of the
common electrode 270. The lower insulating layer 350 is disposed on
the upper surface of the microcavity 305 and the empty portion
305-1 in the column portion of the roof layer 360.
[0072] The roof layer 360 is disposed on the lower insulating layer
350. The roof layer 360 may support the microcavity 305 defined
between the pixel electrode 191 and the common electrode 270, and
may include a photoresist and various organic materials. The roof
layer 360 includes the portion positioned on the microcavity 305
and the column portion positioned at the side of the microcavity
305. The column portion of the roof layer 360 extends substantially
in a vertical direction (e.g., the first direction or the
y-direction), and the column portion may not disposed in the empty
portion 305-1 and the liquid crystal injection hole 307. In the
roof layer 360, the portion positioned on the microcavity 305 may
expose the liquid crystal injection hole 307.
[0073] An upper insulating layer 370 is disposed on the roof layer
360. The upper insulating layer 360 is disposed on the side surface
of the roof layer 360 as well as on the roof layer, thereby having
a structure enclosing the roof layer 360. Referring to FIG. 20 and
FIG. 36, the upper insulating layer 370 may include the inorganic
insulating material such as silicon nitride (SiNx), silicon oxide
(SiOx) and silicon oxynitride (SiOxNy), for example.
[0074] The common electrode 270, the lower insulating layer 350,
the roof layer 360 and the upper insulating layer 370 expose the
liquid crystal injection hole 307 at a side surface thereof to
insert the liquid crystals 310 into the microcavity 305. The liquid
crystal injection hole 307 may be used to remove a sacrificial
layer, which may be provided for forming the microcavity 305.
[0075] A capping layer (not shown) is disposed on the upper
insulating layer 370, thereby enclosing the liquid crystal
injection hole 307. The liquid crystal injection hole 307 is
covered by the capping layer such that the liquid crystal molecules
310 are effectively prevented from being leaked through the liquid
crystal injection hole 307.
[0076] In an exemplary embodiment, a polarizer (now shown) may be
disposed under the substrate and on the capping layer. The
polarizer may include a polarized element that generates
polarization and a tri-acetyl-cellulose ("TAC") layer for ensuring
durability. In an exemplary embodiment, directions of transmissive
axes of an upper polarizer and a lower polarizer may be
substantially perpendicular or parallel to each other.
[0077] Next, an exemplary embodiment of a manufacturing method of a
liquid crystal display according to the invention will be
described.
[0078] FIG. 5 to FIG. 16 are views taken along a line corresponding
to line E-F of FIG. 1, sequentially showing an exemplary embodiment
of a manufacturing method of a liquid crystal display according to
the invention.
[0079] In FIG. 5 to FIG. 16, the microcavity 305 including the
pixel electrode or the structure of the underlying layers of the
sacrificial layer 300 is not shown. In an exemplary embodiment, the
structure of the underlying layers of the sacrificial layer 300 may
be various, and thus processes before providing the sacrificial
layer 300 will be hereinafter omitted.
[0080] Referring to FIG. 5, after providing, e.g., forming, the
passivation layer (not shown) and the pixel electrode (not shown),
the sacrificial layer 300, the common electrode 270, the lower
insulating layer 350 and the photoresist layer 310 are sequentially
provided, e.g., deposited, thereon substantially in an entire
surface thereof. In an exemplary embodiment, the sacrificial layer
300 and the photoresist layer 310 may include the photoresist and
may have substantially the same photo-characteristic. In an
exemplary embodiment, where the sacrificial layer 300 includes a
positive photoresist, the photoresist layer 310 also includes the
positive photoresist. In an alternative exemplary embodiment, where
the sacrificial layer 300 includes a negative photoresist, the
photoresist layer 310 also includes the negative photoresist. In an
exemplary embodiment, the sacrificial layer 300 and the photoresist
layer 310 have substantially the same photo-characteristic, but may
include different materials from each other. Hereinafter, an
exemplary embodiment, where the sacrificial layer 300 and the
photoresist layer 310 include substantially the same photoresist
material, will be described.
[0081] In an exemplary embodiment, the common electrode 270
includes the transparent conductive material such as ITO or IZO,
for example, and the common electrode 270 is provided, e.g.,
deposited, over the sacrificial layer 300. The lower insulating
layer 350 including the inorganic insulating material such as
silicon nitride (SiNx), silicon oxide (SiOx) and silicon oxynitride
(SiOxNy), for example, is provided thereon.
[0082] Next, as shown in FIG. 6, an exposure process is performed
by exposing with light. The characteristic of the underlying
sacrificial layer 300 as well as the photoresist layer 310 is
changed by the exposure process. In FIG. 6, portions of the
sacrificial layer 300 and the photoresist layer 310, in which the
photoresist characteristic thereof are changed by the exposure
process, are indicated by the reference numerals 310-1 and 300-1,
and the oblique lines therein are removed. As described above, in
such an embodiment, the common electrode 270 and the lower
insulating layer 350 positioned on the sacrificial layer 300
include transparent materials such that the exposure process is
effectively performed on the sacrificial layer 300 therebelow. In
an exemplary embodiment, exposure intensity or an exposure amount
may be controlled based on the decreased intensity of the light
reaching the sacrificial layer 300 by the common electrode 270 and
the lower insulating layer 350. The exposure region includes a
region where the sacrificial layer 300 is removed to provide the
liquid crystal injection hole 307. In such an embodiment, the
sacrificial layer 300 in the region corresponding to the column
portion of the roof layer 360 is exposed such that the
characteristic thereof may be changed.
[0083] Next, as shown in FIG. 7, the portion 310-1, where the
characteristic thereof is changed, is developed and removed in the
photoresist layer 310.
[0084] Next, as shown in FIG. 8, the underlying lower insulating
layer 350 is patterned using the photoresist layer 310 as a mask.
In an exemplary embodiment, an etching may be performed through dry
etching or wet etching. In an exemplary embodiment, the lower
insulating layer 350 is etched through the dry etching.
[0085] Next, as shown in FIG. 9, the photoresist layer 310 is
removed through an ashing process.
[0086] Next, as shown in FIG. 10, the common electrode 270 is
etched using the patterned lower insulating layer 350 as a mask.
The etching of the common electrode 270 may be performed through
the dry etching or the wet etching. In one exemplary embodiment,
for example, the wet etching is performed to pattern the common
electrode 270. In such an embodiment, the sacrificial layer 300 is
exposed by the etching of the common electrode 270, and the exposed
position in the sacrificial layer 300 corresponds to the liquid
crystal injection hole 307.
[0087] Next, as shown in FIG. 11, the portion 300-1 of the
sacrificial layer 300 that is exposed through the liquid crystal
injection hole 307 is developed and removed. In an exemplary
embodiment, the characteristic of the portion 300-1 that is
previously exposed in the exposure process described referring to
FIG. 6 is changed such that the portion 300-1 may be removed
through simple developing. In such an embodiment, the sacrificial
layer 300 positioned under the common electrode 270 does not
contact a developer used for developing such that the layer
characteristic of the sacrificial layer 300 is not changed.
Accordingly, in such an embodiment, the sacrificial layer 300 may
be substantially entirely and efficiently and effectively removed
during a process of removing the sacrificial layer 300 thereafter.
Next, in FIG. 11, an additional lower insulating layer 351 is
provided, e.g., deposited, on the entire surface of the substrate.
The additional lower insulating layer 351 may include a material
including the inorganic insulating material such as silicon nitride
(SiNx), silicon oxide (SiOx) and silicon oxynitride (SiOxNy), for
example. According to an alternative exemplary embodiment, the
additional lower insulating layer 351 may be omitted. The
additional lower insulating layer 351 may protect the sacrificial
layer 300 such that the sacrificial layer 300 is effectively
prevented from being removed when developing and patterning the
roof layer 360.
[0088] Next, as shown in FIG. 12, the roof layer 360 is provided on
substantially the entire surface of the substrate. The roof layer
360 may include an organic material or a photoresist material like
the sacrificial layer 300. In an exemplary embodiment, the roof
layer 360 may have substantially the same characteristic as the
sacrificial layer 300, but not being limited thereto. In an
alternative exemplary embodiment, the characteristics of the roof
layer 360 and the sacrificial layer 300 may be different from each
other.
[0089] In an exemplary embodiment, the common electrode 270 and the
lower insulating layer 350 may be removed and then deposited again
on the sacrificial layer 300 before providing the roof layer 360
such that a possibility of the characteristic change of the
sacrificial layer 300, the common electrode 270 and the lower
insulating layer 350 is substantially reduced or minimized.
[0090] Next, as shown in FIG. 13, a portion of the roof layer 360
is exposed. The layer characteristic of the exposed portion 360-1
of the roof layer 360 is changed.
[0091] Next, as shown in FIG. 14, by developing the roof layer 360,
the exposed portion 360-1 thereof is removed such that the roof
layer 360 is patterned. Next, the additional lower insulating layer
351 is etched using the patterned roof layer 360 as a mask. The
additional lower insulating layer 351 may be etched through the wet
etching or the dry etching. In an exemplary embodiment, the
additional lower insulating layer 351 is etched by the dry etching,
such that the side surface of the sacrificial layer 300 is exposed
and the liquid crystal injection hole 307 is thereby formed.
[0092] A length of the roof layer 360 in the vertical direction
(e.g., a height of the roof layer 360) may be equal to or smaller
than a length of the sacrificial layer 300 in the vertical
direction (e.g., a height of the sacrificial layer 300).
[0093] Next, as shown in FIG. 15, the lower insulating layer 350
and the common electrode 270 thereunder are etched using the etched
additional lower insulating layer 351 as a mask. In such an
embodiment, the dry etching may be performed for the different
layers having different characteristics, such that the upper
portion of the sacrificial layer 300 is partially exposed, and the
liquid crystal injection hole 307 becomes further widened.
[0094] Next, as shown in FIG. 16, a stripper is provided through
the liquid crystal injection hole 307 to remove the sacrificial
layer 300 including the photoresist such that the microcavity 305
is provided. In general, when removing the sacrificial layer 300 by
the wet etching, the layer characteristic of the sacrificial layer
300 may be changed by the developer, and a portion of the
sacrificial layer 300 may remain inside the microcavity 305 such
that the cell gap in the microcavity 305 may not be substantially
uniformly maintained. Accordingly, a deterioration of display
quality of the liquid crystal display may occur. In an exemplary
embodiment of the invention, the sacrificial layer 300 under the
common electrode 270 does not contact the developer such that the
layer characteristic is not changed. Accordingly, in such an
embodiment, the etchant such as the stripper is efficiently and
effectively removed such that the sacrificial layer 300 does not
remain in the microcavity 305.
[0095] In an exemplary embodiment, a process of providing the
alignment layer and the liquid crystal layer in the microcavity 305
is performed using the capillary force.
[0096] Next, a process of sealing the microcavity 305 may be
performed by providing a capping layer that effectively prevents
the liquid crystal layer in the microcavity 305 from being
leaked.
[0097] In such an embodiment, a process of attaching a polarizer to
the underside of the substrate and on the capping layer may be
further included.
[0098] In an exemplary embodiment of a method of manufacturing the
liquid crystal display, where the liquid crystal layer is provided
in the microcavity 305, the common electrode 270 is positioned only
on the upper surface of the microcavity 305 and the pixel electrode
is maintained at a predetermined distance from the common electrode
270 such that a short between the pixel electrode and the common
electrode 270 and the display deterioration due to the parasitic
capacitance between the pixel electrode and the common electrode
270 may be effectively prevented.
[0099] Next, an exemplary embodiment of a manufacturing method of a
liquid crystal display will be sequentially described with
reference to FIG. 17 and FIG. 18.
[0100] FIG. 17 and FIG. 18 are cross-sectional views taken along a
line corresponding to line C-D, sequentially showing an exemplary
embodiment of a manufacturing method of a liquid crystal display
according to the invention.
[0101] FIG. 17 is a cross-sectional view corresponding to FIG. 12.
A portion of the sacrificial layer 300 corresponding to line C-D of
FIG. 1 remains when the sacrificial layer 300 is exposed and
developed such that the layered structure is shown in FIG. 17 is
provided.
[0102] Next, the roof layer 360 is exposed and developed to form a
liquid crystal injection hole 307.
[0103] Next, as shown in FIG. 18, the sacrificial layer 300 exposed
through the liquid crystal injection hole 307 is removed by wet
etching to form the microcavity 305. In FIG. 18, a portion
including a connection 305-1 that connects the adjacent
microcavities 305 is shown.
[0104] Next, an alternative exemplary of a manufacturing method of
a liquid crystal display will be described with reference to FIG.
19 to FIG. 21.
[0105] FIG. 19 to FIG. 21 are cross-sectional views sequentially
showing an alternative exemplary embodiment of a manufacturing
method of a liquid crystal display according to the invention.
[0106] FIG. 19 shows a process that may be performed after the
process described with reference to FIG. 14. In an exemplary
embodiment, as shown in FIG. 19, an upper insulating layer 370
covering the entire surface of the roof layer 360 and the substrate
is provided. The upper insulating layer 370 may include the
inorganic insulating material such as silicon nitride (SiNx),
silicon oxide (SiOx) and silicon oxynitride (SiOxNy), for
example.
[0107] Next, as shown in FIG. 20, the material of the upper
insulating layer 370 covering the liquid crystal injection hole 307
is etched to expose a portion of the sacrificial layer 300. In an
exemplary embodiment, a photoresist pattern that exposes the liquid
crystal injection hole 307 on the upper insulating layer 370 may be
provided, and the dry etching may be performed using the
photoresist pattern as a mask.
[0108] Next, as shown in FIG. 21, the exposed sacrificial layer 300
is wet etched and removed.
[0109] In the exemplary embodiment of the manufacturing method
shown in FIG. 19 to FIG. 21, the roof layer 360 is protected by the
upper insulating layer 370 such that the roof layer 360 is
protected when wet-etching the sacrificial layer 300. In such an
embodiment, the roof layer 360 and the sacrificial layer 300 may
include substantially the same material as each other.
[0110] Next, another alternative exemplary embodiment of a
manufacturing method of a liquid crystal display according to the
invention will be described with reference to FIG. 22 to FIG.
33.
[0111] FIG. 22 to FIG. 33 are cross-sectional views sequentially
showing an alternative exemplary embodiment of a manufacturing
method of a liquid crystal display according to the invention.
[0112] FIG. 22 to FIG. 33 are the cross-sectional views taken along
a line corresponding to line E-F of the liquid crystal display of
FIG. 1 as FIG. 5 to FIG. 16, and the microcavity 305 including the
pixel electrode or the structure of the underlying layers of the
sacrificial layer 300 are not shown. The structure of the
underlying layers may be variously modified, and thus, processes
after a process of providing the sacrificial layer 300 will now be
described in detail.
[0113] Firstly, referring to FIG. 22, the sacrificial layer 300,
the common electrode 270 and the photoresist layer 310 are
continuously deposited on the entire surface of a passivation layer
(not shown) and a pixel electrode (not shown) after providing the
passivation layer and the pixel electrode. In such an embodiment,
the sacrificial layer 300 and the photoresist layer 310 may include
the photoresist and also have substantially the same
photocharacteristic. In an exemplary embodiment, where the
sacrificial layer 300 includes a positive photoresist, the
photoresist layer 310 includes the positive photoresist. In an
alternative exemplary embodiment, where the sacrificial layer 300
includes a negative photoresist, the photoresist layer 310 includes
the negative photoresist. In such an embodiment, where the
sacrificial layer 300 and the photoresist layer 310 have
substantially the same photocharacteristic, the sacrificial layer
300 and the photoresist layer 310 may include different materials
from each other.
[0114] In an exemplary embodiment, the common electrode 270
includes the transparent conductive material such as ITO or IZO,
for example, and the common electrode 270 is provided under the
sacrificial layer 300 and the photoresist layer 310.
[0115] Next, as shown in FIG. 23, an exposure process is performed
with light. In an exemplary embodiment, the photoresist layer 310
and the underlying sacrificial layer 300 are exposed by the
exposure process such that the characteristic thereof is changed.
In FIG. 23, portions of the sacrificial layer 300 and the
photoresist layer 310, in which the photoresist characteristic
thereof are changed by the exposure process, are indicated by the
reference numerals 310-1 and 300-1, and the oblique lines therein
are removed. As described above, in such an embodiment, the common
electrode 270 and the lower insulating layer 350 positioned on the
sacrificial layer 300 include transparent materials such that the
exposure process is effectively performed on the sacrificial layer
300 therebelow. In an exemplary embodiment, exposure intensity or
an exposure amount may be controlled based on the decreased
intensity of the light reaching the sacrificial layer 300 by the
common electrode 270 and the lower insulating layer 350. The
exposure region includes a region where the sacrificial layer 300
is removed to provide the liquid crystal injection hole 307. In
such an embodiment, the sacrificial layer 300 in the region
corresponding to the column portion of the roof layer 360 is
exposed such that the characteristic thereof may be changed.
[0116] Next, as shown in FIG. 24, the portion 310-1 where the
characteristic thereof is changed is developed and removed in the
photoresist layer 310.
[0117] Next, as shown in FIG. 25, the common electrode 270 is
etched using the pattern of the photoresist layer 310 as a mask to
form the liquid crystal injection hole 307 exposing the sacrificial
layer 300. The etching may be performed through dry etching or wet
etching. In one exemplary embodiment, for example, the common
electrode 270 is etched through the wet etching.
[0118] Next, as shown in FIG. 26, the photoresist layer 310 is
removed through an ashing process. In such an embodiment, the
portion 300-1 exposed through the liquid crystal injection hole 307
is partially removed. Also, the portion of the sacrificial layer
300 covered by the common electrode 270 is partially removed such
that an undercut structure U is formed under the common electrode
270.
[0119] Next, as shown in FIG. 27, the portion 300-1 of the
sacrificial layer 300 exposed through the liquid crystal injection
hole 307 is removed. The characteristic of the portion 300-1 that
is exposed in the exposure process shown in FIG. 23 is already
changed such that the portion 300-1 may be removed through the
simple developing. In such an embodiment, the sacrificial layer 300
positioned under the common electrode 270 does not contact a
developer which may be used when developing the portion 300-1 of
the sacrificial layer 300 such that the characteristic of the
sacrificial layer 300 is not changed, and the sacrificial layer 300
is thereby substantially entirely and effectively removed during a
process for removing the sacrificial layer 300 thereafter.
[0120] Next, as shown in FIG. 28, the lower insulating layer 350 is
provided, e.g., deposited, on the entire surface of the substrate.
The lower insulating layer 350 includes the material including the
inorganic insulating material such as silicon nitride (SiNx),
silicon oxide (SiOx) and silicon oxynitride (SiOxNy), for example.
The lower insulating layer 350 may protect the sacrificial layer
300 such that the sacrificial layer 300 is effectively prevented
from being removed when developing and patterning the roof layer
360.
[0121] Next, as shown in FIG. 29, the roof layer 360 is provided,
e.g., deposited, on the entire surface of the substrate. The roof
layer 360 may include the organic material or the photoresist
material as the sacrificial layer 300. The roof layer 360 may have
substantially the same characteristic as the sacrificial layer 300,
but not being limited thereto. In an alternative exemplary
embodiment, the characteristics of the roof layer 360 and the
sacrificial layer 300 may be different from each other.
[0122] Next, as shown in FIG. 30, a portion of the roof layer 360
is exposed such that the characteristic of the exposed portion
360-1 of the roof layer 360 is changed.
[0123] Next, as shown in FIG. 31, the exposed portion 360-1 is
removed by developing the roof layer 360 such that the roof layer
360 is patterned. The length of the roof layer 360 in a vertical
direction (e.g., height of the roof layer 360) may be equal to or
less than a length of the sacrificial layer 300 in the vertical
direction (e.g., height of the sacrificial layer 300).
[0124] Next, as shown in FIG. 32, the lower insulating layer 350
and the common electrode 270 are etched using the patterned roof
layer 360 as a mask such that the liquid crystal injection hole 307
exposing the sacrificial layer 300 is provided. In an exemplary
embodiment, the lower insulating layer 350 and the common electrode
270 may be etched by the dry etching.
[0125] Next, as shown in FIG. 33, a stripper is provided through
the liquid crystal injection hole 307 to remove the sacrificial
layer 300 including the photoresist such that the microcavity 305
is provided. In general, when removing the sacrificial layer 300 by
the wet etching, the layer characteristic of the sacrificial layer
300 may be changed by the developer, and the material of the
partial sacrificial layer 300 may remain inside the microcavity
305, such that the cell gap in the microcavity 305 may not be
substantially uniformly maintained. Accordingly, a deterioration of
display quality of the liquid crystal display may occur. In an
exemplary embodiment of the invention, the sacrificial layer 300
under the common electrode 270 does not contact the developer such
that the layer characteristic is not changed. Accordingly, in an
exemplary embodiment, the etchant such as the stripper is
efficiently and effectively removed such that the sacrificial layer
300 does not remain in the microcavity 305.
[0126] In an exemplary embodiment, a process of providing the
alignment layer and the liquid crystal layer in the microcavity 305
is performed using capillary force.
[0127] Next, a process of sealing the microcavity 305 may be
performed by providing a capping layer that effectively prevents
the liquid crystal layer in the microcavity 305 from being
leaked.
[0128] In such an embodiment, the process of attaching the
polarizer to the underside of the substrate and on the capping
layer may be further included.
[0129] In an exemplary embodiment of a method of manufacturing a
liquid crystal display, where the liquid crystal layer is provided
in the microcavity 305, the common electrode 270 is positioned only
on the upper surface of the microcavity 305, and the pixel
electrode is maintained at a predetermined distance from the common
electrode 270 such that a short between the pixel electrode and the
common electrode 270 and the display deterioration due to the
parasitic capacitance between the pixel electrode and the common
electrode 270 may be effectively prevented.
[0130] Next, an alternative exemplary embodiment of a manufacturing
method of a liquid crystal display will be described with reference
to FIG. 34 to FIG. 36.
[0131] FIG. 34 to FIG. 36 are cross-sectional views sequentially
showing an alternative exemplary embodiment of a manufacturing
method of a liquid crystal display according to the invention.
[0132] FIG. 34 shows a process that may be performed after the
process described with reference to FIG. 31. In an exemplary
embodiment, as shown in FIG. 34, an upper insulating layer 370 is
provided to cover the entire surface of the roof layer 360 and the
substrate. The upper insulating layer 370 may include the inorganic
insulating material such as silicon nitride (SiNx), silicon oxide
(SiOx) and silicon oxynitride (SiOxNy), for example.
[0133] Next, as shown in FIG. 35, the upper insulating layer 370
covering the liquid crystal injection hole 307 is etched to expose
a portion of the sacrificial layer 300. In an exemplary embodiment,
a photoresist pattern exposing the liquid crystal injection hole
307 on the upper insulating layer 370 may be provided, and the dry
etching may be performed using the photoresist pattern as a
mask.
[0134] Next, as shown in FIG. 36, the exposed sacrificial layer 300
is wet etched and removed.
[0135] In the exemplary embodiment of the manufacturing method
shown in FIG. 34 to FIG. 36, the roof layer 360 is protected by the
upper insulating layer 370 such that the roof layer 360 is
protected when wet-etching the sacrificial layer 300. In such an
embodiment, the roof layer 360 and the sacrificial layer 300 may
include substantially the same material.
[0136] In the exemplary embodiments described above, a structure
under the microcavity 305 may have various structures. The
structure under the microcavity 305 may include the thin film
transistor, the wiring, the pixel electrode, the color filter and
the light blocking member. Hereinafter, an exemplary embodiment of
the liquid crystal display will be described with reference to FIG.
37.
[0137] FIG. 37 is a top plan view of a pixel of an exemplary
embodiment of a liquid crystal display according to the
invention.
[0138] FIG. 37 shows an exemplary embodiment where a pixel
including subpixels that are defined by adjacent microcavities 305
positioned upwardly and downwardly with respect to the liquid
crystal injection hole 307, respectively.
[0139] In an exemplary embodiment, a gate line 121 and a storage
voltage line 131 are disposed on an insulation substrate including
a transparent glass or plastic. The gate line 121 includes a first
gate electrode 124a, a second gate electrode 124b and a third gate
electrode 124c of a pixel. The storage voltage line 131 includes
storage electrodes 135a and 135b, and a protrusion 134 protruding
in a direction toward the gate line 121. The storage electrodes
135a and 135b of the pixel have a structure surrounding a first
subpixel electrode 192h of the pixel and a second subpixel
electrode 192l of an upper pixel. In such an embodiment, as shown
in FIG. 37, a horizontal portion 135b of the storage electrode may
be a wire connected to a horizontal portion 135b of an adjacent
pixel (e.g., a left side pixel or a right side pixel).
[0140] A gate insulating layer (not shown) is disposed on the gate
line 121 and the storage voltage line 131. A semiconductor (not
shown) positioned below a data line 171, a semiconductor (not
shown) positioned below source/drain electrodes, and a
semiconductor 154 positioned at a channel portion of a thin film
transistor are disposed on the gate insulating layer.
[0141] A plurality of ohmic contacts (not shown) may be disposed on
each of the semiconductors 154 and between the data line 171 and
source/drain electrodes.
[0142] In such an embodiment, data conductors 171, 173a, 173b,
173c, 175a, 175b and 175c, which include the data line 171
including a first source electrode 173a and a second source
electrode 173b, a first drain electrode 175a, a second drain
electrode 175b, a third source electrode 173c, and a third drain
electrode 175c, are disposed on the semiconductors 154 and the gate
insulating layer.
[0143] In such an embodiment, the first gate electrode 124a, the
first source electrode 173a and the first drain electrode 175a
collectively define a first thin film transistor together with the
semiconductor 154, and a channel of the thin film transistor is
formed at the semiconductor portion 154 between the first source
electrode 173a and the first drain electrode 175a. Similarly, the
second gate electrode 124b, the second source electrode 173b and
the second drain electrode 175b collectively define a second thin
film transistor together with the semiconductor 154, and a channel
of the thin film transistor is formed at the semiconductor portion
154 between the second source electrode 173b and the second drain
electrode 175b. The third gate electrode 124c, the third source
electrode 173c and the third drain electrode 175c collectively
define a third thin film transistor together with the semiconductor
154, and a channel of the thin film transistor is formed at the
semiconductor portion 154 between the third source electrode 173c
and the third drain electrode 175c.
[0144] In an exemplary embodiment, the data line 171 has a
structure in which a width thereof becomes smaller in a region of
the thin film transistor in the vicinity of an extension 175c' of
the third drain electrode 175c such that an interval of the data
line 171 from adjacent wiring is effectively maintained and signal
interference between the data line 171 and the adjacent wiring is
substantially reduced, but not being limited thereto.
[0145] A first passivation layer (not shown) is disposed on the
data conductors 171, 173c, 175a, 175b and 175c and an exposed
portion of the semiconductor 154. The first passivation layer may
include an inorganic insulator such as silicon nitride (SiNx),
silicon oxynitride (SiOxNy) and silicon oxide (SiOx), for example,
or an organic insulator.
[0146] A color filter 230 is disposed on the passivation layer.
Color filters 230 of the same color are disposed along pixels
arranged in a same direction (e.g., a data line direction). Also,
color filters 230 of different colors are disposed in pixels
adjacent in a horizontal direction (e.g., a gate line direction),
and adjacent color filters 230 may overlap the data line 171. The
color filters 230 may display one of primary colors such as three
primary colors of red, green and blue, for example, but not being
limited thereto. In one alternative exemplary embodiment, for
example, the color filters 230 may display one of cyan, magenta,
yellow and white colors.
[0147] A light blocking member 220 (e.g., a black matrix) is
disposed on the color filter 230. The light blocking member 220 is
disposed in a region (hereafter referred to as "a transistor
formation region") where the gate line 121, the thin film
transistor and the data line 171 are disposed, and has a lattice
structure having openings corresponding to a region where an image
is displayed. The color filter 230 is disposed in the opening of
the light blocking member 220. Also, the light blocking member 220
may include a material that blocks light.
[0148] A second passivation layer (not shown) is disposed on the
color filter 230 and the light blocking member to cover the color
filter 230 and the light blocking member 220. The second
passivation layer may include an inorganic insulator such as
silicon nitride (SiNx), silicon oxynitride (SiOxNy) and silicon
oxide (SiOx), for example, or an organic insulator. According to an
exemplary embodiment, where a step occurs due to a thickness
difference between the color filter 230 and the light blocking
member 220, the second passivation layer including an organic
insulator substantially reduces or effectively removes the step
difference.
[0149] A first contact hole 186a and a second contact hole 186b,
which expose the first drain electrode 175a and extensions 175b' of
the second drain electrode 175b, respectively, are formed through
the color filter 230, the light blocking member 220 and the
passivation layers. In such an embodiment, a third contact hole
186c, which exposes the protrusion 134 of the storage voltage line
131 and the extension 175c' of the third drain electrode 175c, is
formed through the color filter 230, the light blocking member 220
and the passivation layers.
[0150] In an exemplary embodiment, where the contact holes 186a,
186b and 186c are formed through the light blocking member 220 and
the color filter 230 by etching the light blocking member 220 and
the color filter 230, the light blocking member 220 or the color
filter 230 may be previously removed at the position corresponding
to the contact holes 186a, 186b and 186c, as the light blocking
member 220 or the color filter 230 may not be effectively etched
together with the passivation layers due to the different layer
characteristics thereof.
[0151] In an exemplary embodiment, the contact holes 186a, 186b and
186c may be formed by changing a position of the light blocking
member 220 and etching only the color filter 230 and the
passivation layers.
[0152] A pixel electrode including the first subpixel electrode
192h and the second subpixel electrode 192l is disposed on the
second passivation layer. The pixel electrode may include a
transparent conductive material such as ITO or IZO, for
example.
[0153] In an exemplary embodiment, the first subpixel electrode
192h and the second subpixel electrode 192l are adjacent to each
other in a column direction, have a substantially quadrangular
shape, and include a cross-shaped stem including a transverse stem
and a longitudinal stem crossing the transverse stem. In an
exemplary embodiment, the first subpixel electrode 192h and the
second subpixel electrode 192l are divided into four subregions by
the transverse stem and the longitudinal stem, and each subregion
includes a plurality of minute branches.
[0154] The minute branches of the first subpixel electrode 192h and
the second subpixel electrode 192l form angles in a range of about
40 degrees to 45 degrees with the gate line 121 or the transverse
stem. In an exemplary embodiment, the minute branches of two
adjacent subregions may be substantially perpendicular to each
other. In such an embodiment, a width of the minute branch may
become gradually changes or intervals between minute branches may
be different from each other.
[0155] The first subpixel electrode 192h and the second subpixel
electrode 192l are physically and electrically connected to the
first drain electrode 175a and the second drain electrode 175b
through the contact holes 186a and 186b, and receive data voltages
from the first drain electrode 175a and the second drain electrode
175b.
[0156] In an exemplary embodiment, a connecting member 194 that
electrically connects the extension 175c' of the third drain
electrode 175c and the protrusion 134 of the storage voltage line
131 through the third contact hole 186c is included such that a
portion of the data voltage applied to the second drain electrode
175b is divided through the third source electrode 173c and thus
the magnitude of a voltage applied to the second subpixel electrode
192l may become smaller than the magnitude of a voltage applied to
the first subpixel electrode 192h.
[0157] In an exemplary embodiment, an area of the second subpixel
electrode 192l may be greater than or equal to an area of the first
subpixel electrode 192h and less than twice the area of the first
subpixel electrode 192h.
[0158] In an exemplary embodiment, an opening for collecting gas
discharged from the color filter 230 and an overcoat that covers
the opening and including a material substantially the same as the
pixel electrode 192 (collectively 192h and 192l) thereon may be
provided on the second passivation layer. The opening and the
overcoat have structures for blocking the gas discharged from the
color filter 230 from being transferred to another element, but may
be omitted in an alternative exemplary embodiment.
[0159] In such an embodiment, a microcavity 305 is defined on the
second passivation layer and the pixel electrode 192, and a liquid
crystal layer is disposed in the microcavity 305.
[0160] In such an embodiment, the upper structure above the
microcavity 305 may be substantially the same as the structure
shown in FIG. 1 to FIG. 4, and any repetitive detailed description
thereof will hereinafter be omitted.
[0161] The position and structure of the wiring, the pixel
electrode and the thin film transistor in the pixel of exemplary
embodiment of a liquid crystal display is not limited to the
exemplary embodiment shown in FIG. 37, but may be variously
modified.
[0162] While this invention has been described in connection with
what is presently considered to be practical exemplary embodiments,
it is to be understood that the invention is not limited to the
disclosed embodiments, but, on the contrary, is intended to cover
various modifications and equivalent arrangements included within
the spirit and scope of the appended claims.
* * * * *