Active solid-state devices (e.g. – transistors – solid-state diode – Non-single crystal – or recrystallized – semiconductor... – Amorphous semiconductor material
Reexamination Certificate
2000-09-26
2003-04-08
Flynn, Nathan J. (Department: 2826)
Active solid-state devices (e.g., transistors, solid-state diode
Non-single crystal, or recrystallized, semiconductor...
Amorphous semiconductor material
C257S057000, C257S072000, C349S042000, C349S043000
Reexamination Certificate
active
06545292
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a thin film transistor-liquid crystal display (hereinafter referred to as a TFT-LCD) and a manufacturing method therefor. More particularly, this invention relates to a TFT-LCD and a manufacturing method therefor which etches multi-layer patterns in a single process step.
2. Description of the Related Art
A conventional TFT-LCD is disclosed in Society for Information Display '94 DIGEST, page 263, the content of which is hereby expressly incorporated by reference herein in its entirety. That TFT-LCD will now be described with reference to
FIGS. 1
,
2
A-
2
H, and
3
A-
3
H.
In
FIG. 1
, a conventional TFT-LCD is depicted which comprises: a substrate
1
, a gate electrode
2
, an anodic oxidation layer
3
, an insulating layer
4
, an amorphous silicon layer
5
, an n+ amorphous silicon layer
6
, a source/drain electrode
9
, a passivation layer
10
, and a pixel electrode layer
13
.
FIGS. 2A-2H
show several cross-sectional views depicting different stages of a fabrication sequence for the conventional TFT-LCD shown in FIG.
1
.
FIGS. 3A-3H
show cell views of layouts corresponding to the steps illustrated in
FIGS. 2A-2H
, respectively. Some layers are omitted from the cell layout views of
FIGS. 3A-3H
for purposes of simplification. Referring to those figures, a conventional method for fabricating a TFT-LCD generally comprises the steps of:
forming a gate pad
21
, a gate electrode
2
, and a gate line by depositing and etching a metal layer on a substrate
1
;
forming a anodic oxidation layer
3
on both the gate electrode
2
and a portion of the gate pad
21
;
depositing an insulating layer
4
;
depositing an amorphous silicon layer
5
on the insulating layer
4
;
depositing an n+ amorphous silicon layer
6
on the amorphous silicon layer
5
;
etching both the amorphous silicon layer
5
and the n+ amorphous silicon layer
6
to form an active island
56
;
partially etching the insulating layer
4
on the gate pad
21
;
forming both a source/drain electrode
9
and a data line by depositing and etching a metal layer;
forming a passivation layer
10
having a contact hole
12
by depositing and etching an insulating material; and
forming a pixel electrode
13
by depositing and etching a transparent conductive material.
The above-described conventional TFT-LCD has many problems.
First, it reduces production yield. In addition, the etchants used during the etching process steps cause defects in the resulting TFT-LCD.
Moreover, it is more costly because many etching processes are employed in its fabrication.
SUMMARY OF THE INVENTION
An objective of the present invention is to provide a TFT LCD and a manufacturing method therefor which etches multi-layer patterns in a single process step. Accordingly, the present invention not only reduces the number of masking processes but also produces a high quality device with less defects.
In order to achieve this objective, a method is provided for manufacturing a TFT-LCD according to the present invention, which comprises the steps of:
depositing a gate metal on a substrate;
forming a gate electrode and a gate pad by etching the gate metal;
depositing an insulating layer;
depositing an amorphous silicon layer;
depositing an n+ amorphous silicon layer on the amorphous silicon layer.
depositing a source/drain layer on the n+ amorphous silicon layer;
etching the source/drain layer, the n+ amorphous silicon layer, and the amorphous silicon layer to form a triple layer pattern in a single process step;
etching the source/drain layer and the n+ amorphous silicon layer to form a source/drain electrode pattern;
depositing a passivation layer;
etching a passivation layer to expose both a portion of the source/drain electrode and a portion of the gate pad;
depositing a pixel electrode on the passivation layer; and
etching the pixel electrode;
A TFT-LCD according to the present invention includes: a gate electrode and a gate pad that are formed on a substrate; an insulating layer having a contact hole exposing the gate pad; an amorphous silicon layer which is formed on the insulating layer; a source/drain electrode which is formed on the amorphous silicon layer; a passivation layer, having contact holes which are formed on both the source/drain electrode and the gate pad; and a pixel electrode layer formed on the passivation layer.
REFERENCES:
patent: 5045485 (1991-09-01), Tanaka et al.
patent: 5054887 (1991-10-01), Kato et al.
patent: 5166085 (1992-11-01), Wakai et al.
patent: 5289016 (1994-02-01), Noguchi
patent: 5294811 (1994-03-01), Aoyama et al.
patent: 5334859 (1994-08-01), Matsuda
patent: 5397719 (1995-03-01), Kim et al.
patent: 5422293 (1995-06-01), Konya
patent: 5478766 (1995-12-01), Park et al.
patent: 5483082 (1996-01-01), Takizawa et al.
patent: 5496749 (1996-03-01), Nasu et al.
patent: 5580796 (1996-12-01), Takizawa et al.
patent: 56140321 (1981-11-01), None
patent: 6-118444 (1994-04-01), None
Glueck, et al. “18.4: A 14-in.-Diagonal a-Si TFT=AMLCD for PAL-TV”, Society for Information Display '94 Digest, pp. 263-266, 1994.
Flynn Nathan J.
Forde Remmon R.
McGuireWoods LLP
Park Hae-Chan
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