Thin film transistor substrate having color filter with reverse taper shape
View Patent ↗A thin film transistor substrate includes a color filter layer and a gate line. The color filter layer has a reverse taper shape, which is used to pattern the gate line without a separate mask. Thus, the total number of masks used to manufacture the thin film transistor substrate can be reduced, thereby reducing the manufacturing cost and improving the productivity.
1. A thin film transistor substrate comprising:
a base substrate including a pixel area having a switching area, a first line area adjacent to the pixel area, and a second line area adjacent to the pixel area and crossing the first line area;
a color filter arranged in the pixel area except the switching area and in the second line area and having a reverse taper shape;
a gate line arranged in the first line area and spaced apart from the color filter;
a data line overlying the color filter in the second line area;
a thin film transistor arranged in the switching area and electrically connected to the gate line and the data line; and
a pixel electrode overlying the color filter and electrically connected to the thin film transistor.
2. The thin film transistor substrate of claim 1 , wherein the gate line comprises a first gate line layer and a second gate line layer on the first gate line layer.
3. The thin film transistor substrate of claim 2 , wherein the first gate line layer is made of a different material than the data line, and the second gate line layer is made of the same material as the data line.
4. The thin film transistor substrate of claim 3 , further comprising a gate insulating layer overlying the gate line.
5. The thin film transistor substrate of claim 4 , further comprising a semiconductor line overlying the gate insulating layer, wherein the thin film transistor comprises a semiconductor layer merging with the semiconductor line.
6. The thin film transistor substrate of claim 5 , wherein the semiconductor layer comprises an active layer having a thickness of about 1500 angstroms to about 2500 angstroms and an ohmic contact layer having a thickness of about 400 angstroms to about 600 angstroms, the color filter has a thickness of about 10000 angstroms to about 15000 angstroms, the gate line has a thickness of about 4000 angstroms to about 5000 angstroms, and the gate insulating layer has a thickness of about 1500 angstroms to about 2500 angstroms.
7. The thin film transistor substrate of claim 4 , further comprising a floating line that is arranged between the gate insulating layer and the color filter in the data line's area.
8. The thin film transistor substrate of claim 3 , wherein the first gate line layer is made of the same material as the pixel electrode.
9. The thin film transistor substrate of claim 3 , further comprising a protective layer overlying the data line and the thin film transistor.
10. The thin film transistor substrate of claim 9 , wherein the protective layer does not overlap with the pixel electrode.
11. The thin film transistor substrate of claim 3 , further comprising a protective layer covering the data line, part of the protective area being disposed under the pixel electrode, the protective layer having a contact hole formed therethrough to a portion of a drain electrode of the thin film transistor.