U.S. patent application number 11/163394 was filed with the patent office on 2006-02-23 for pixel structure.
Invention is credited to Han-Chung Lai.
Application Number | 20060038180 11/163394 |
Document ID | / |
Family ID | 35908811 |
Filed Date | 2006-02-23 |
United States Patent
Application |
20060038180 |
Kind Code |
A1 |
Lai; Han-Chung |
February 23, 2006 |
PIXEL STRUCTURE
Abstract
A pixel structure is provided. The pixel structure comprises a
scan line, a data line, a pixel electrode and a thin film
transistor. The data line branches out into a plurality of
subsidiary lines in the area above the scan line. If there is a
short circuit between the scan line and the data line, the short
circuit can be repaired by cutting the connections to one of the
branching subsidiary lines. In one embodiment of this invention, a
repair line is set up on one side of the data line such that a
portion of the repair line crosses over the scan line. If there is
a short circuit between the scan line and the data line, a laser
repair operation can be carried out through the repair line.
Inventors: |
Lai; Han-Chung; (Taoyuan
Hsien, TW) |
Correspondence
Address: |
JIANQ CHYUN INTELLECTUAL PROPERTY OFFICE
7 FLOOR-1, NO. 100
ROOSEVELT ROAD, SECTION 2
TAIPEI
100
TW
|
Family ID: |
35908811 |
Appl. No.: |
11/163394 |
Filed: |
October 17, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10604981 |
Aug 29, 2003 |
|
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11163394 |
Oct 17, 2005 |
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Current U.S.
Class: |
257/72 ; 257/59;
438/151; 438/157 |
Current CPC
Class: |
H01L 27/124 20130101;
G02F 1/136272 20210101; G02F 1/136263 20210101; G02F 1/136259
20130101 |
Class at
Publication: |
257/072 ;
257/059; 438/151; 438/157 |
International
Class: |
H01L 29/04 20060101
H01L029/04 |
Claims
1. A pixel structure formed on a transparent substrate, comprising:
a first conductive layer formed on a transparent substrate, wherein
the first conductive layer comprises a scan line and a gate, the
gate and the scan line being electrically connected together; a
first dielectric layer formed on the transparent substrate covering
the first conductive layer; a channel layer formed over the first
dielectric layer above the gate; a second conductive layer formed
over the first dielectric layer, wherein the second conductive
layer comprises a data line, a repair line and a source/drain such
that the gate, the channel layer and the source/drain together
constitute a thin film transistor, and the repair line is
positioned on one side of the data line with a portion of the
repair line crossing over the scan line; a second dielectric layer
formed on the first dielectric layer covering the second conductive
layer; and a pixel electrode formed over the second dielectric
layer, wherein the pixel electrode, the data line and the
source/drain are electrically connected together.
2. The pixel structure of claim 1, wherein the repair line
furthermore comprises a first end and a second end such that the
first end of the repair line and the data line are electrically
connected but the second end of the repair line has no electrical
connection with the data line.
3. The pixel structure of claim 1, wherein the repair line
furthermore comprises a first end and a second end such that both
the first end and the second end have no electrical connection with
the data line.
4. The pixel structure of claim 1, wherein the second dielectric
layer has a contact opening such that the pixel electrode and the
source/drain are electrically connected through a contact inside
the contact opening.
5. The pixel structure of claim 1, wherein material constituting
the pixel electrode is selected from a group consisting of
indium-tin oxide and indium-zinc oxide.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of a prior application Ser.
No. 10/604,981, filed Aug. 29, 2003, which claims the priority
benefit of Taiwan application serial No. 92107253, filed Mar. 31,
2003. All disclosures are incorporated herewith by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] The present invention relates to a pixel structure. More
particularly, the present invention relates to a pixel structure
having a mechanism for repairing possible short-circuits between a
scan line and a data line.
[0004] 2. Description of Related Art
[0005] With the rapid advance in semiconductor technologies and
man-machine interface designs, multi-media are now at the forefront
of communication. In a multi-media world, displays are important
devices. Although the cathode ray tube (CRT) is economical to
produce and has advantages in many aspects, possible production of
hazardous radiation, a bulky body and enormous power consumption
are three major factors that diminish its desirableness in a
multi-terminal desktop environment. With better resolution, space
utilization and power consumption, the thin film transistor liquid
crystal display (TFT-LCD) has been developed to serve as a
substitute the CRT.
[0006] FIG. 1 is a schematic top view of a conventional pixel
structure repaired through a laser chemical vapor deposition (CVD).
As shown in FIG. 1, a conventional pixel structure 100 comprises a
scan line 102, a data line 104, a thin film transistor 106 and a
pixel electrode 108. The thin film transistor 106 furthermore
comprises a gate 106a, a channel layer 106b and a source/drain
106c. The gate 106 and the scan line 102 are electrically connected
together. Similarly, the source/drain 106c, the data line 104 and
the pixel electrode 108 are electrically connected together.
[0007] The scan line 102 is part of a first metallic layer (metal
1) and the data line 104 is part of a second metallic layer (metal
2). Hence, the scan line 102 and the data line 104 are electrically
isolated from each other through a first dielectric layer (a gate
insulation layer). In addition, a second dielectric layer (a
passivation layer) is also formed over the data line 104. However,
a short circuit in the cross over region between the scan line 102
and the data line 104 is possible due to some defects in the
dielectric layer, e.g., impurities or particles contamination. Most
short-circuits between the scan line 102 and the data line 104 can
be repaired. To repair the short circuit, the data line 104 at both
ends of a short-circuited region is severed (as shown by the dash
line). Thereafter, two repair openings 110 are formed in the second
dielectric layer. A laser chemical vapor deposition (CVD) process
is performed to form a thin metallic layer 112 linking up the
severed data line 104 through the repair openings 110. In other
words, the severed data line 104 is reconnected after the
reparation.
[0008] In a conventional laser repair, the thin metallic line 112
must cross over the scan line 102 to link up both ends of the
severed data line 104. Thus, the thin metallic line 112 usually has
a considerable length resulting in a longer and costlier
repair.
SUMMARY OF THE INVENTION
[0009] Accordingly, one object of the present invention is to
provide a pixel structure that uses a short laser repair route for
repairing any short-circuits between a scan line and a data
line.
[0010] A second object of this invention is to provide a pixel
structure that does not require any laser repair when there is any
short-circuit between a scan line and a data line.
[0011] To achieve these and other advantages and in accordance with
the purpose of the invention, as embodied and broadly described
herein, the invention provides a first pixel structure for
fabricating on a transparent substrate. The pixel structure
comprises a first conductive layer, a first dielectric layer, a
channel layer, a second conductive layer, a second dielectric layer
and a pixel electrode. The first conductive layer furthermore
comprises a scan line and a gate. The gate and the scan line are
electrically connected. The first dielectric layer is formed over
the transparent substrate covering the first conductive layer. The
channel layer is formed over the first dielectric layer above the
gate. The second conductive layer is formed over the first
dielectric layer. The second conductive layer furthermore comprises
a data line and a source/drain. The gate, the channel layer and the
source/drain together constitute a thin film transistor. In
addition, the data line that corresponds to an area above the scan
line branches out into a plurality of subsidiary lines. The second
dielectric layer is formed over the first dielectric layer covering
the second conductive layer. The pixel electrode is formed over the
second dielectric layer. The pixel electrode, the data line and the
source/drain are electrically connected together.
[0012] In the pixel structure of this invention, the width of the
scan line underneath the data line covered area is smaller than the
width of the scan line elsewhere.
[0013] In the pixel structure of this invention, the second
dielectric layer furthermore has a contact opening such that the
pixel electrode and the source/drain are electrically connected
though a contact inside the contact opening. In addition, the pixel
electrode is fabricated using a material including, for example,
indium-tin oxide (ITO) or indium-zinc oxide (IZO).
[0014] This invention also provides a second pixel structure for
fabricating on a transparent substrate. The pixel structure
comprises a first conductive layer, a first dielectric layer, a
channel layer, a second conductive layer, a second dielectric layer
and a pixel electrode. The first conductive layer furthermore
comprises a scan line and a gate. The gate and the scan line are
electrically connected. The first dielectric layer is formed over
the transparent substrate covering the first conductive layer. The
channel layer is formed over the first dielectric layer above the
gate. The second conductive layer is formed over the first
dielectric layer. The second conductive layer furthermore comprises
a data line, a repair line and a source/drain. The gate, the
channel layer and the source/drain together constitute a thin film
transistor. In addition, the repair line is positioned on one side
of the data line crossing over the scan line. The second dielectric
layer is formed over the first dielectric layer covering the second
conductive layer. The pixel electrode is formed over the second
dielectric layer. The pixel electrode, the data line and the
source/drain are electrically connected together.
[0015] In the pixel structure of this invention, one end of the
repair line connects electrically with the data line but the other
end of the repair line has no connection with the data line.
Alternatively, both ends of the repair line have no connection with
the data line.
[0016] It is to be understood that both the foregoing general
description and the following detailed description are exemplary,
and are intended to provide further explanation of the invention as
claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The accompanying drawings are included to provide 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.
[0018] FIG. 1 is a schematic top view of a conventional pixel
structure repaired through a laser chemical vapor deposition
(CVD).
[0019] FIGS. 2A to 2D are schematic top views showing the
progression of steps for fabricating a pixel structure according to
a first preferred embodiment of this invention.
[0020] FIGS. 3A to 3D are schematic cross-sectional views along
line I-I of FIGS. 2A to 2D respectively.
[0021] FIGS. 4 and 5 are schematic top views showing two processes
for laser-repairing the pixel structure according to the first
embodiment of this invention.
[0022] FIG. 6 is a schematic top view showing a pixel structure
according to a second preferred embodiment of this invention.
[0023] FIGS. 7 and 8 are schematic top views showing two processes
for laser-repairing the pixel structure according to the second
embodiment of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] 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.
[0025] FIGS. 2A to 2D are schematic top views showing the
progression of steps for fabricating a pixel structure according to
a first preferred embodiment of this invention. FIGS. 3A to 3D are
schematic cross-sectional views along line 1-1 of FIGS. 2A to 2D
respectively. As shown in FIGS. 2A and 3A, a transparent substrate
200 such as a glass substrate or a plastic substrate is provided. A
first conductive layer (M1) is formed over the transparent
substrate 200. The first conductive layer MI has two sections
including a scan line 202 and a gate 204. The gate 204 and the scan
line 202 are connected together. Thereafter, a first dielectric
layer 206 is formed over the transparent substrate 200 covering the
scan line 202 and the gate 204.
[0026] As shown in FIGS. 2B and 3B, a channel layer 208 is formed
over the first dielectric layer. The channel layer 208 is
positioned over the gate 204.
[0027] As shown in FIGS. 2C and 3C, a second conductive layer M2 is
formed over the channel layer 208. The second conductive layer M2
has two sections including a data line 210 and a pair of
source/drain 212. The source/drain 212 are positioned on each side
of the channel layer 208 with one of the source/drain 212
electrically connected to the data line 210. In addition, the data
line 210 in the area above the scan line 202 branches into a
plurality of subsidiary lines 210a and 210b, for example. The
stacked structure that includes the gate 204, the channel layer
208, the source/drain 212 together constitute a thin film
transistor T. Thereafter, a second dielectric layer 214 is formed
over the scan line 202, the data line 210 and the entire thin film
transistor T.
[0028] As shown in FIGS. 2D and 3D, a contact opening 214a is
formed in the second dielectric layer 214. Thereafter, a pixel
electrode 216 is formed over the second dielectric layer 214 so
that the pixel electrode 216 and one end of the source/drain 212
are electrically connected through a contact in the contact opening
214a.
[0029] In brief, the pixel structure mainly comprises a first
conductive layer M1, a first dielectric layer 206, a channel layer
208, a second conductive layer M2, a second dielectric layer 214
and a pixel electrode 216. The first conductive layer M1
furthermore comprises a scan line 202 and a gate 204. The gate 204
and the scan line 202 are electrically connected. The first
dielectric layer 206 is positioned over the transparent substrate
200 to cover the first conductive layer M1. The channel layer 208
is positioned over the first dielectric layer 206 above the gate
204. The second conductive layer M2 is positioned over the first
dielectric layer 206. The second conductive layer M2 furthermore
comprises a data line 210 and a pair of source/drain 212. The data
line 210 in the area above the scan line 202 branches into a
plurality of subsidiary lines 210a, 210b. Furthermore, the gate
204, the channel layer 208 and the source/drain 212 together
constitute a thin film transistor T. The second dielectric layer is
positioned over the first dielectric layer 206 to cover the second
conductive layer M2. The pixel electrode 216 is positioned over the
second dielectric layer 214. The pixel electrode 216, the data line
210 and the source/drain 212 are electrically connected. Moreover,
the pixel electrode 216 is fabricated using a material including,
for example, indium-tin oxide (ITO) or indium-zinc oxide (IZO).
[0030] FIGS. 4 and 5 are schematic top views showing two processes
for laser-repairing the pixel structure according to the first
embodiment of this invention. In FIG. 4, the data line 210 splits
up into several subsidiary lines 210a, 210b (two lines in FIG. 4)
in the area above the scan line 202. If one of the subsidiary lines
210b happens to have a short circuit with the scan line 202 due to
defects caused by impurities or particles contamination, the
short-circuited subsidiary line 210b is cut along the dashed line.
Thereafter, a pair of repair openings 218 is formed in the second
dielectric layer (not shown) and then a thin metallic layer 220 is
formed between the repair openings 218 by performing a laser
chemical vapor deposition (CVD) process. The thin metallic layer
220 reconnects the severed subsidiary line 210b together through
the contact inside the repair openings 218.
[0031] However, those skilled in the art may notice that forming a
thin metallic layer to reconnect the severed subsidiary data line
210b is redundant because the data line 210 still remains connected
through the branch line 210a.
[0032] As shown in FIG. 5, the overlapping area with the scan line
202 increases correspondingly when the number of subsidiary lines
is increased. To prevent too much parasitic capacitance resulting
from an increase in the overlapping of area, the scan line pattern
is slightly modified in this embodiment so that the width of the
scan line 202 is smaller at the cross over area of the subsidiary
lines 210a and 210b.
[0033] FIG. 6 is a schematic top view showing a pixel structure
according to a second preferred embodiment of this invention. The
pixel structure in this embodiment is similar to the one in the
first embodiment. One major difference between the two is that a
repair line 300 is formed on one side of the data line 210. The
repair line 300 functions in a way similar to the branching
subsidiary lines in the first embodiment of this invention.
[0034] FIGS. 7 and 8 are schematic top views showing two processes
for laser-repairing the pixel structure according to the second
embodiment of this invention. In FIG. 7, a first end 300a of the
repair line 300 connects with the data line 210 but a second end
300b of the repair line 300 has no connection with the data line
210. If there is a short circuit between the scan line 202 and the
data line 210, the section of the data line 210 having the
short-circuiting is severed along the dashed lines. Thereafter, a
repair opening 302 is formed at the second end 300b of the repair
line. A thin metallic layer 304 is formed between the second end
300b of the repair line 300 and the data line 210 by performing a
laser chemical vapor deposition (CVD) process. In other words, the
thin metallic layer 304 reconnects the severed data line 210
through the repair line 300 and the thin metallic layer 304.
[0035] In FIG. 8, however, neither end of the repair line 300 has a
direct connection with the data line 210. If there is a short
circuit between the scan line 202 and the data line 210, the
section of the data line 210 having the short-circuiting is severed
along the dashed lines. Thereafter, a repair opening 302 is formed
at the first end 300a and the second end 300b of the repair line
300. Finally, a thin metallic layer 304 is formed between each of
the repair openings 302 and corresponding severed ends of the data
line 210.
[0036] In summary, the pixel structure of this invention has at
least the following advantages.
[0037] 1. Due to the provision of a plurality of branching
subsidiary data lines in the area above the scan line, a short
circuit in one of the branching data lines can be repaired by
severing the short-circuiting section of that particular branch
without performing a laser repair.
[0038] 2. Since a short thin metallic layer for connecting one end
or both ends of a repair line to a severed data line needs to be
formed in a laser repair operation, the reparation can be carried
out cheaper and faster.
[0039] 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.
* * * * *