U.S. patent application number 12/242938 was filed with the patent office on 2010-01-07 for method for fabricating pixel structure.
This patent application is currently assigned to AU OPTRONICS CORPORATION. Invention is credited to Chia-Ming Chang, Jun-Kai Chang, Chun-Yi Chiang, Han-Tang Chou, Hsiang-Chih Hsiao, Zong-Long Jhang, Che-Yung Lai, Ta-Wen Liao, Chia-Chi Tsai, Chen-Pang Tung, Chou-Huan Yu.
Application Number | 20100003792 12/242938 |
Document ID | / |
Family ID | 41464701 |
Filed Date | 2010-01-07 |
United States Patent
Application |
20100003792 |
Kind Code |
A1 |
Lai; Che-Yung ; et
al. |
January 7, 2010 |
METHOD FOR FABRICATING PIXEL STRUCTURE
Abstract
A pixel structure fabricating method is provided. A gate and a
gate insulation layer covering the gate are formed on a substrate.
A channel layer is formed on the gate insulation layer. A
conductive layer is formed on the channel layer and gate insulation
layer. A black matrix having a color filer layer accommodating
opening is formed on the conductive layer. The black matrix
includes a first block and a second block which is thicker than the
first block. The conductive layer is patterned with the black
matrix as a mask to form a source and a drain on the channel layer.
A color filter layer is formed within the color filter layer
accommodating opening through inkjet printing. A dielectric layer
is formed on the black matrix and color filter layer. The
dielectric layer is patterned to expose the drain. A pixel
electrode electrically connected to the drain is formed.
Inventors: |
Lai; Che-Yung; (Taichung
County, TW) ; Jhang; Zong-Long; (Taichung City,
TW) ; Tsai; Chia-Chi; (Taipei City, TW) ;
Tung; Chen-Pang; (Taipei City, TW) ; Chang;
Chia-Ming; (Taipei County, TW) ; Chiang; Chun-Yi;
(Taichung City, TW) ; Yu; Chou-Huan; (Taichung
County, TW) ; Hsiao; Hsiang-Chih; (Keelung City,
TW) ; Chou; Han-Tang; (Taoyuan County, TW) ;
Chang; Jun-Kai; (Chiayi City, TW) ; Liao; Ta-Wen;
(Hsinchu County, TW) |
Correspondence
Address: |
JIANQ CHYUN INTELLECTUAL PROPERTY OFFICE
7 FLOOR-1, NO. 100, ROOSEVELT ROAD, SECTION 2
TAIPEI
100
TW
|
Assignee: |
AU OPTRONICS CORPORATION
Hsinchu
TW
|
Family ID: |
41464701 |
Appl. No.: |
12/242938 |
Filed: |
October 1, 2008 |
Current U.S.
Class: |
438/160 ;
257/E21.414 |
Current CPC
Class: |
G02F 1/136213 20130101;
G02F 1/136227 20130101; G02F 1/136209 20130101; H01L 27/1214
20130101; G02F 1/136222 20210101; H01L 27/1288 20130101; H01L
27/1248 20130101 |
Class at
Publication: |
438/160 ;
257/E21.414 |
International
Class: |
H01L 21/336 20060101
H01L021/336 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 7, 2008 |
TW |
97125584 |
Claims
1. A pixel structure fabricating method, comprising: forming a gate
on a substrate; forming a gate insulation layer on the gate;
forming a channel layer on the gate insulation layer; forming a
conductive layer on the channel layer and the gate insulation
layer; forming a photosensitive black matrix on the conductive
layer, wherein the photosensitive black matrix has a color filter
layer accommodating opening, the photosensitive black matrix
includes a first block and a second block, and the thickness of the
first block is smaller than the thickness of the second block;
patterning the conductive layer with the photosensitive black
matrix as a mask to form a source and a drain on the channel layer,
wherein the gate, the channel layer, the source, and the drain form
a thin film transistor (TFT); forming a color filter layer within
the color filter layer accommodating opening through an inkjet
printing process; forming a dielectric layer on the photosensitive
black matrix and the color filter layer; patterning the dielectric
layer to expose the drain; and forming a pixel electrode
electrically connected to the drain.
2. The pixel structure fabricating method according to claim 1,
further comprising forming a protecting layer on the photosensitive
black matrix, the TFT, and the gate insulation layer.
3. The pixel structure fabricating method according to claim 1,
wherein the step of patterning the conductive layer comprises:
removing part of the conductive layer not covered by the
photosensitive black matrix with the photosensitive black matrix as
a mask to form the source and the drain on the channel layer; and
reducing the thickness of the photosensitive black matrix until the
first block is completely removed.
4. The pixel structure fabricating method according to claim 3,
wherein the step of removing part of the conductive layer not
covered by the photosensitive black matrix comprises performing a
wet etching process.
5. The pixel structure fabricating method according to claim 3,
wherein the step of reducing the thickness of the photosensitive
black matrix comprises performing a dry etching process.
6. The pixel structure fabricating method according to claim 5,
wherein the dry etching process comprises an ashing process.
7. The pixel structure fabricating method according to claim 1,
wherein the step of forming the channel layer comprises: forming a
semiconductor material layer on the gate insulation layer; and
patterning the semiconductor material layer to form a semiconductor
layer.
8. The pixel structure fabricating method according to claim 7,
further comprising forming an ohmic contact layer on the
semiconductor layer.
9. The pixel structure fabricating method according to claim 8,
wherein the step of patterning the conductive layer comprises:
removing part of the conductive layer not covered by the
photosensitive black matrix with the photosensitive black matrix as
a mask to form the source and the drain on the channel layer; and
removing the ohmic contact layer on the channel layer, and reducing
the thickness of the photosensitive black matrix until the first
block is completely removed.
10. The pixel structure fabricating method according to claim 9,
wherein the step of removing the ohmic contact layer on the channel
layer and reducing the thickness of the photosensitive black matrix
comprises performing a dry etching process.
11. The pixel structure fabricating method according to claim 1,
wherein the step of patterning the dielectric layer comprises:
forming a photoresist layer on the dielectric layer; and removing
part of the dielectric layer and part of the photosensitive black
matrix with the photoresist layer as a mask to form a first opening
and a second opening in the dielectric layer and the photosensitive
black matrix, respectively.
12. The pixel structure fabricating method according to claim 1,
wherein the step of forming the pixel electrode comprises: forming
an electrode material layer on the dielectric layer, the
photosensitive black matrix, and the drain; and patterning the
electrode material layer.
13. The pixel structure fabricating method according to claim 1,
wherein a first capacitance electrode is further formed while
forming the gate, a second capacitance electrode is further formed
while forming the source and the drain, and the first capacitance
electrode and the second capacitance electrode form a storage
capacitor.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority benefit of Taiwan
application serial no. 97125584, filed on Jul. 7, 2008. The
entirety of the above-mentioned patent application is hereby
incorporated by reference herein and made a part of this
specification.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention generally relates to a method for
fabricating a pixel structure, and more particularly, to a method
for fabricating a pixel structure having a color filter layer
through photo engraving processes (PEP).
[0004] 2. Description of Related Art
[0005] Liquid crystal display (LCD) has replaced cathode ray tube
(CRT) display as the mainstream in the display market because it
has such advantages as high image quality, small volume, light
weight, low driving voltage, low power consumption, and broad
application, etc. A conventional LCD panel is composed of a color
filter substrate having a color filter layer, a thin film
transistor (TFT) array substrate, and a liquid crystal layer
disposed between foregoing two substrates. In order to increase the
resolution of the LCD panel and the aperture ratio of the pixels
and to avoid alignment error between the color filter substrate and
the TFT array substrate, a technique for integrating the color
filter layer directly into the TFT array substrate (color filter on
array, COA) is further provided.
[0006] FIGS. 1A.about.1G are diagrams illustrating a conventional
technique for forming a color filter layer on a TFT array
substrate, wherein three pixel structures are illustrated as
examples. First, referring to FIG. 1A, a substrate 10 is provided,
and a gate 20 is formed on the substrate 10 through a first photo
engraving process (PEP). Then, referring to FIG. 1B, a gate
insulation layer 30 is formed on the substrate 10 to cover the gate
20, and a channel layer 40 and an ohmic contact layer 42 are formed
on the gate insulation layer 30 above the gate 20 through a second
PEP. Next, referring to FIG. 1C, a source 50 and a drain 60 are
formed on part of the channel layer 40 and part of the gate
insulation layer 30 through a third PEP. Generally speaking, the
channel layer 40 is made of amorphous silicon (a-Si), and the ohmic
contact layer 42 is made of N-type heavily-doped a-Si such that the
contact resistance between the channel layer 40 and the source 50
and the contact resistance between the channel layer 40 and the
drain 60 can be reduced. The ohmic contact layer 42 is formed by
performing N-type ion doping on the surface of a-Si.
[0007] Referring to FIG. 1C again, the source 50 and the drain 60
are respectively extended from both sides of the channel layer 40
onto the gate insulation layer 30 and expose parts of the channel
layer 40, wherein the gate 20, the channel layer 40, the source 50,
and the drain 60 form a TFT TH. Then, referring to FIG. 1D, a
dielectric layer 70 covering the TFT TH is formed, and a red color
filter pattern 82 is formed above the TFT TH through a fourth PEP,
wherein the red color filter pattern 82 has a contact opening H1
which is located above the drain 60 of the TFT TH corresponding to
the red color filter pattern 82.
[0008] After that, referring to FIG. 1E, a green color filter
pattern 84 is formed above part of the TFT TH through a fifth PEP,
and a contact opening H2 is formed within the green color filter
pattern 84, wherein the contact opening H2 is located above the
drain 60 of the TFT TH corresponding to the green color filter
pattern 84. Next, referring to FIG. 1F, a blue color filter pattern
86 is formed above the remaining TFT TH through a sixth PEP, and a
contact opening H3 is formed within the blue color filter pattern
86, wherein the contact opening H3 is located above the drain 60 of
the TFT TH corresponding to the blue color filter pattern 86. As
shown in FIGS. 1D.about.1F, the color filter layer 80 composed of
the red color filter pattern 82, the green color filter pattern 84,
and the blue color filter pattern 86 is fabricated through three
PEPs.
[0009] Thereafter, referring to FIG. 1G, the dielectric layer 70
exposed by the contact openings H1, H2, and H3 is removed through
an etching process. After that, a pixel electrode 90 is formed on
the color filter layer 80 through a seventh PEP. As shown in FIG.
1G, the pixel electrodes 90 of the pixel structures are
electrically connected to the corresponding drains 60 respectively
through the contact openings H1, H2, and H3. By now, the process
for directly integrating the color filter layer 80 into the TFT
array substrate is completed.
[0010] As described above, the conventional method for fabricating
a color filter layer on a TFT array substrate requires at least
seven PEPs therefore is very complicated and requires very high
fabricating cost. In addition, masks having different patterns are
required for fabricating the pixel structure through foregoing at
least seven PEPs, and accordingly, the fabricating cost of the
pixel structure cannot be reduced due to the high cost of these
masks.
SUMMARY OF THE INVENTION
[0011] Accordingly, the present invention is directed to a method
for fabricating a pixel structure, wherein the fabricating cost of
the pixel structure is reduced.
[0012] The present invention provides a method for fabricating a
pixel structure. First, a gate is formed on a substrate. Then, a
gate insulation layer is formed on the substrate to cover the gate.
Next, a channel layer is formed on the gate insulation layer. After
that, a conductive layer is formed on the channel layer and the
gate insulation layer. Next, a photosensitive black matrix is
formed on the conductive layer, wherein the photosensitive black
matrix has a color filter layer accommodating opening and includes
a first block and a second block, and the thickness of the first
block is smaller than that of the second block. Thereafter, the
conductive layer is patterned with the photosensitive black matrix
as a mask to form a source and a drain on the channel layer,
wherein the gate, the channel layer, the source, and the drain form
a thin film transistor (TFT). After that, a color filter layer is
formed within the color filter layer accommodating opening through
an inkjet printing process. Then, a dielectric layer is formed on
the photosensitive black matrix and the color filter layer.
Thereafter, the dielectric layer is patterned to expose the drain.
Next, a pixel electrode electrically connected to the drain is
formed.
[0013] According to an embodiment of the present invention, the
pixel structure fabricating method further includes forming a
protecting layer on the photosensitive black matrix, the TFT, and
the gate insulation layer.
[0014] According to an embodiment of the present invention, the
step for patterning the conductive layer includes following steps.
First, part of the conductive layer not covered by the
photosensitive black matrix is removed with the photosensitive
black matrix as a mask to form the source and the drain on the
channel layer. Then, the thickness of the photosensitive black
matrix is reduced until the first block is completely removed.
[0015] According to an embodiment of the present invention, the
step of removing part of the conductive layer not covered by the
photosensitive black matrix includes performing a wet etching
process.
[0016] According to an embodiment of the present invention, the
step of reducing the thickness of the photosensitive black matrix
includes performing a dry etching process.
[0017] According to an embodiment of the present invention, the dry
etching process includes an ashing process.
[0018] According to an embodiment of the present invention, the
step of forming the channel layer includes forming a semiconductor
material layer on the gate insulation layer and patterning the
semiconductor material layer to form a semiconductor layer.
[0019] According to an embodiment of the present invention, the
pixel structure fabricating method further includes forming an
ohmic contact layer on the semiconductor layer.
[0020] According to an embodiment of the present invention, the
step of patterning the dielectric layer includes forming a
photoresist layer on the dielectric layer and removing part of the
dielectric layer and part of the photosensitive black matrix with
the photoresist layer as a mask to respectively form a first
opening and a second opening in the dielectric layer and the
photosensitive black matrix.
[0021] According to an embodiment of the present invention, the
step of forming the pixel electrode includes forming an electrode
material layer on the dielectric layer, the photosensitive black
matrix and the drain and, patterning the electrode material
layer.
[0022] According to an embodiment of the present invention, a first
capacitance electrode is further formed while forming the gate, a
second capacitance electrode is further formed while forming the
source and the drain, and the first capacitance electrode and the
second capacitance electrode form a storage capacitor.
[0023] In the present invention, a color filter layer is fabricated
above a TFT through an inkjet printing process. Thereby, compared
to the conventional method for fabricating a pixel structure, the
method in the present invention offers a simplified process and
reduced fabricating cost of masks. In addition, the material used
for forming the color filter layer can be effectively reduced by
forming the color filter layer through the inkjet printing process,
and accordingly the fabricating cost of the pixel structure can be
further reduced. Moreover, in the present invention, the conductive
layer is etched with a photosensitive black matrix as a mask. Thus,
fewer PEPs are performed in the present invention and accordingly
the fabricating cost of the pixel structure is reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The accompanying drawings are included to provide a further
understanding of the invention, and are incorporated in and
constitute a part of this specification. The drawings illustrate
embodiments of the invention and, together with the description,
serve to explain the principles of the invention.
[0025] FIGS. 1A.about.1G are diagrams illustrating a conventional
technique for forming a color filter layer on a TFT array
substrate, wherein three pixel structures are illustrated as
examples.
[0026] FIGS. 2A.about.2J are cross-sectional views illustrating a
method for fabricating a pixel structure according to an embodiment
of the present invention.
[0027] FIGS. 3A.about.3F are respectively top views of FIG. 2A,
FIG. 2B, FIG. 2E, FIG. 2G, FIG. 2I, and FIG. 2J.
[0028] FIG. 4 is a cross-sectional view of a pixel structure
according to another embodiment of the present invention.
DESCRIPTION OF THE EMBODIMENTS
[0029] Reference will now be made in detail to the present
preferred embodiments of the invention, examples of which are
illustrated in the accompanying drawings. Wherever possible, the
same reference numbers are used in the drawings and the description
to refer to the same or like parts.
[0030] FIGS. 2A.about.2J are cross-sectional views illustrating a
method for fabricating a pixel structure according to an embodiment
of the present invention. FIGS. 3A.about.3F are respectively top
views of FIG. 2A, FIG. 2B, FIG. 2E, FIG. 2G, FIG. 2I, and FIG.
2J.
[0031] Referring to both FIG. 2A and FIG. 3A, first, a substrate
210 is provided, wherein the substrate 210 may be a hard substrate
or a soft substrate made of glass or plastic. Then, a gate 220 is
formed on the substrate 210. The gate 220 may be formed by forming
a conductive layer (not shown) on the substrate 210 first and then
patterning the conductive layer, wherein the conductive layer may
be formed through sputtering, evaporation, or other suitable film
deposition techniques, and the conductive layer may be patterned
through a photo engraving process (PEP) or photolithography etching
process. In addition, in the present embodiment, a first
capacitance electrode C1 may be selectively formed while forming
the gate 220.
[0032] Next, referring to FIG. 2B and FIG. 3B, a gate insulation
layer 230 covering the gate 220 and the first capacitance electrode
C1 is formed on the substrate 210. The gate insulation layer 230
may be formed through chemical vapour deposition (CVD) or other
suitable film deposition techniques, and the gate insulation layer
230 may be made of a dielectric material, such as SiO, SiN, and
SiON. After that, referring to FIG. 2B and FIG. 3B again, a channel
layer CH is formed on the gate insulation layer 230, wherein the
channel layer CH may be made of amorphous silicon (a-Si) or other
suitable semiconductor materials. The channel layer CH may be
formed by forming a semiconductor material layer (not shown) on the
gate insulation layer 230 and then patterning the semiconductor
material layer to form a semiconductor layer (i.e., the channel
layer CH).
[0033] In addition, as shown in FIG. 2B and FIG. 3B, in order to
reduce the contact resistances between the channel layer CH and the
source and drain formed subsequently, in the present embodiment, an
ohmic contact layer O may be further formed selectively on the
channel layer CH when the channel layer CH is formed, wherein the
ohmic contact layer O may be made of N-type heavily-doped a-Si.
[0034] Thereafter, referring to FIG. 2C, a conductive layer 240 is
formed on the channel layer CH and the gate insulation layer 230.
Then, referring to FIG. 2C again, a photosensitive black matrix 250
is formed on the conductive layer 240, wherein the photosensitive
black matrix 250 has at least one color filter layer accommodating
opening 252. Besides, the photosensitive black matrix 250 includes
a first block 254 and a second block 256, and the thickness T1 of
the first block 254 is smaller than the thickness T2 of the second
block 256. The photosensitive black matrix 250 may be made of
photosensitive black resin.
[0035] Referring to FIG. 2C again, the photosensitive black matrix
250 may be formed through following steps. First, a photosensitive
black resin layer (not shown) is formed on the conductive layer
240. Then, a half-tone mask S is provided, wherein the half-tone
mask S has at least one transmissive region S1, at least one
semi-transparent region S2, and at least one non-transmissive S3,
wherein the transmittance of the semi-transparent region S2 is
between the transmittance of the transmissive region S1 and the
transmittance of the non-transmissive region S3. After that, the
photosensitive black resin layer is exposed and developed by using
the half-tone mask S to form the photosensitive black matrix
250.
[0036] Next, referring to FIG. 2E and FIG. 3C, the conductive layer
240 is patterned with the photosensitive black matrix 250 as a mask
to form a source 242 and a drain 244 on the channel layer CH. The
gate 220, the channel layer CH, the source 242, and the drain 244
form a TFT TH. It should be noted that in the present embodiment,
the conductive layer 240 is patterned by using the photosensitive
black matrix 250 as a mask. Thus, fewer PEPs are performed in the
present embodiment and accordingly the fabricating cost of the
pixel structure is reduced. In addition, in the present embodiment,
a second capacitance electrode C2 may be selectively formed while
patterning the conductive layer 240, wherein the first capacitance
electrode C1 and the second capacitance electrode C2 form a storage
capacitor C.
[0037] In the present embodiment, the conductive layer 240 may be
patterned through following steps. First, referring to FIG. 2D,
part of the conductive layer 240 not covered by the photosensitive
black matrix 250 is removed with the photosensitive black matrix
250 as a mask to form the source 242 and the drain 244 on the
channel layer CH. The conductive layer 240 not covered by the
photosensitive black matrix 250 may be removed through a wet
etching process. Then, referring to FIG. 2E, the ohmic contact
layer O on the channel layer CH is removed, and the thickness of
the photosensitive black matrix 250 is reduced until the first
block 254 is completely removed and part of the conductive layer
240 is exposed. The step of removing the ohmic contact layer O on
the channel layer CH and reducing the thickness of the
photosensitive black matrix 250 includes performing a dry etching
process to the ohmic contact layer O and the photosensitive black
matrix 250, wherein the dry etching process performed to the
photosensitive black matrix 250 may be an ashing process.
[0038] After that, referring to FIG. 2F, a protecting layer P may
be selectively formed on the photosensitive black matrix 250, the
TFT TH, and the gate insulation layer 230 to protect the conductive
layer 240 exposed by the photosensitive black matrix 250. The
protecting layer P may be made of an inorganic dielectric material,
such as Silicon oxide, Silicon nitride, and Silicon oxide nitride.
To be more specific, the protecting layer P may be formed through
physical vapour deposition (PVD) or CVD.
[0039] Next, referring to FIG. 2G and FIG. 3D, a color filter layer
260 is formed within the color filter layer accommodating opening
252 through an inkjet printing process. The color filter layer 260
may be made of acrylic resin. Substantially, in the technique for
directly integrating the color filter layer into a TFT array
substrate, each pixel structure has a color filter layer 260
located above the TFT TH, and the color filter layer 260 may
include a red color filter pattern, a green color filter pattern,
and a blue color filter pattern to allow an LCD panel to achieve a
full-color display effect.
[0040] To be more specific, the color filter layer 260 may be a red
color filter pattern, a green color filter pattern, or a blue color
filter pattern. Besides, the inkjet printing process may include
following steps. First, a surface treatment is performed to the
substrate 210, and then, a nozzle filled with red, green, or blue
ink is used for filling the ink into the predetermined red, green,
or blue color filter layer accommodating opening 252. After that, a
baking process is performed to solidify the ink and form the color
filter layer 260.
[0041] It should be noted that in the present embodiment, the color
filter layer 260 is formed through an inkjet printing process
instead of the PEP in the conventional technique. Thus, in the
present embodiment, the fabricating cost is greatly reduced, the
fabricating process is simplified, and accordingly the production
yield is improved. In addition, compared to the conventional
technique wherein the red, green, and blue color filter layers 260
have to be formed individually, the present embodiment offers a
shortened process time by forming these color filter layers 260
simultaneously. However, the color, number, and disposition of the
color filter patterns are not limited in the present invention;
instead, they can be adjusted according to the actual
requirement.
[0042] Next, referring to FIG. 2H, a dielectric layer 270 is formed
on the photosensitive black matrix 250 and the color filter layer
260, wherein the dielectric layer 270 may be made of an organic
dielectric material, such as acrylic resin and photosensitive
resin, and the dielectric layer 270 may be formed through
photoresist coating. After that, referring to FIG. 2I and FIG. 3E,
the dielectric layer 270 is patterned to expose the drain 244. To
be specific, the dielectric layer 270 may be patterned through
following steps. First, referring to FIG. 2H, a photoresist layer
PR is formed on the dielectric layer 270. Then, referring to FIG.
2I, part of the dielectric layer 270, part of the protecting layer
P, and part of the photosensitive black matrix 250 are removed with
the photoresist layer PR as a mask to respectively form a first
opening OP1 and a second opening OP2 in the dielectric layer 270
and the photosensitive black matrix 250. Besides, the first opening
OP1 and the second opening OP2 expose the drain 244 and the second
capacitance electrode C2. After that, the photoresist layer PR is
removed.
[0043] Referring to FIG. 2J and FIG. 3F, a pixel electrode 280
electrically connected to the drain 244 is formed. In the present
embodiment, the pixel electrode 280 is electrically connected to
the second capacitance electrode C2 through the first opening OP1
and the second opening OP2 so that the first capacitance electrode
C1, the gate insulation layer 230, and the pixel electrode 280 form
a metal/insulator/ITO (MII) storage capacitor. The pixel electrode
280 may be formed by first forming an electrode material layer (not
shown) on the dielectric layer 270, the photosensitive black matrix
250, and the drain 244 and then patterning the electrode material
layer, wherein the electrode material layer may be an indium tin
oxide (ITO) layer or an indium zinc oxide (IZO) layer formed
through sputtering.
[0044] A pixel structure 200 is fabricated through foregoing steps
illustrated in FIGS. 2A.about.2J. It should be noted that unlike
the conventional technique which requires at least seven PEPs for
fabricating the pixel electrode 200, the color filter layer 260 can
be directly integrated into the TFT TH array substrate 210 through
only five PEPs and an inkjet printing process in the present
embodiment. Thus, the present embodiment offers a simplified
fabricating process and reduces the fabricating cost. Moreover, in
the present embodiment, the color filter layer 260 is formed
through an inkjet printing process. Thus, the material used for
forming the color filter layer 260 is effectively reduced and
accordingly the fabricating cost of the pixel structure is further
reduced.
[0045] FIG. 4 is a cross-sectional view of a pixel structure
according to another embodiment of the present invention. Referring
to FIG. 4, in the present embodiment, the pixel structure 400 is
similar to the pixel structure 200 (as shown in FIG. 2J), and the
difference between the two is that the pixel structure 400 does not
have any protecting layer.
[0046] In overview, the pixel structure fabricating method provided
by the present invention has at least following advantages:
[0047] 1. according to the pixel structure fabricating method
provided by the present invention, no PEP is performed for forming
the color filter layer. Thus, the fabricating cost of
high-precision masks used in the PEP can be skipped;
[0048] 2. since the process for fabricating a pixel structure is
simplified, defects caused during the PEPs (such as photoresist
coating, soft baking, hard baking, exposing, developing, and
photoresist removing etc) can be avoided;
[0049] 3. since the color filter layer is formed through an inkjet
printing process, compared to the conventional technique wherein a
PEP is performed for the same purpose, the material used for
forming the color filter layer is effectively reduced and
accordingly the fabricating cost of the pixel structure is also
reduced; and
[0050] 4. in the present invention, the conductive layer is etched
with a photosensitive black matrix as a mask. Thus, fewer PEPs are
performed and according the fabricating cost is reduced.
[0051] It will be apparent to those skilled in the art that various
modifications and variations can be made to the structure of the
present invention without departing from the scope or spirit of the
invention. In view of the foregoing, it is intended that the
present invention cover modifications and variations of this
invention provided they fall within the scope of the following
claims and their equivalents.
* * * * *