Thin film transistor array substrate and manufacturing method thereof
View Patent ↗A thin film transistor array substrate, and manufacturing methods thereof, having a dual data link structure comprised of a first data link made from a gate metal layer and of a second data link made from a transparent conductive layer. A gate pad made from the gate metal layer electrically connects directly with the first data link, and to the second data link via a data pad protection electrode that passes through contact holes. The data pad protection electrode makes surface connections to the data pad. A data line is electrically connected via a contact electrode to the first data link. The data line and the data pad are formed from different metal layers. The data pad is protected by a gate insulating layer. The contact electrode is extended from the second data link.
1. A method of manufacturing a thin film transistor array substrate of a liquid crystal display, comprising the steps of:
(A) forming on a substrate a gate line and a crossing data line that are separated by a gate insulating film, a thin film transistor adjacent to the crossing, a gate link and a gate pad that extends from the gate line, a data pad under the gate insulating film, and a data link that extends from the data pad toward the data line;
(B) forming a protective film over the entire surface of the substrate after completing step (A);
(C) defining a plurality of first contact holes and second contact holes through the protective film and through the gate insulating film; wherein the first contact holes expose the data link, and wherein the second contact holes expose the data pad;
(D) defining a plurality of third contact holes through the protective film, wherein the third contact holes expose the data line;
(E) forming a pixel electrode that is electrically connected to the thin film transistor and a data pad protection electrode that is connected to the data link via the first contact holes, to the data pad via the second contact holes, and to the data line via the third contact holes.
2. The method as claimed in claim 1 , wherein step (A) includes:
depositing a gate metal material onto the substrate and then patterning the gate metal material to form a gate electrode of the thin film transistor, the gate line, the gate pad, the data pad and the data link;
forming the gate insulating film;
depositing a semiconductor material on the gate insulating film and then patterning the semiconductor material to form an active layer;
depositing a semiconductor material on the active layer and then patterning the semiconductor material to form an ohmic contact layer of the thin film transistor; and
depositing a drain metal material over the semiconductor material and the gate insulating film, and then patterning the drain metal material to form the data line and source and drain electrodes of the thin film transistor.
3. The method as claimed in claim 1 , wherein the step of forming the data pad protection electrode includes forming the data pad protection electrode from the same material as the pixel electrode.
4. The method as claimed in claim 3 , wherein the step of forming the data pad protection electrode includes forming the data pad protection electrode from a transparent material.
5. The method as claimed in claim 4 , wherein the step of forming the data pad protection electrode includes forming the data pad protection electrode from a material selected from the group consisting of ITO, TO, IZO, and combinations thereof.
6. The method as claimed in claim 1 , wherein the step of forming the data line includes forming the data line from molybdenum.
7. The method as claimed in claim 1 , wherein the step of forming the third contact holes includes forming the third contact holes through the data line such that the data line is exposed through the sides of the third contact holes, and wherein the step of forming the data pad protection electrode includes forming the data pad protection electrode in electrical contact with the data line along the sides of the third contact holes.