TFT-LCD array substrate and manufacturing method thereof

#Embodiments of the present invention relate to a thin film transistor liquid crystal display (TFT-LCD) and a method of manufacturing the same.

#Thin film transistor liquid crystal displays (TFT-LCDs) have the advantages of small volume, low energy consumption, low radiation, etc., and are gradually prevailing in the market of flat plate displays. A TFT-LCD is mainly constituted by an array substrate and a color filter substrate assembled to face to each other. A plurality of thin film transistors and a plurality of pixel electrodes are arranged on the array substrate in matrix, and each of the pixel electrodes is controlled by a thin film transistor. The pixel electrode is charged when the thin film transistor is turned-on. After charging, the voltage of the pixel electrode remains unchanged until the next time of turn-on of the thin film transistor.

#Because of parasitic capacitance between the drain electrode and the gate electrode of the thin film transistor, a kickback voltage ΔVp is generated at the moment the charging of the pixel electrode is finished. The kickback voltage ΔVp is expressed as follows:

#The present invention will become more fully understood from the detailed description given hereinafter and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention and wherein:

#FIG. 1 is a plan view showing a first embodiment of a TFT-LCD array substrate according to the invention;

#FIG. 2 is a sectional view taken along line A1-A1 in FIG. 1;

#Hereinafter, the embodiments of the invention will be described in detail with reference to the accompanying drawings.

#FIG. 1 is a plan view showing a first embodiment of a TFT-LCD array substrate according to the invention, FIG. 2 is a sectional view taken along line A1-A1 in FIG. 1, and FIG. 3 is a sectional view taken along line B1-B1 in FIG. 1.

#As shown in FIG. 1 to FIG. 3, the TFT-LCD array substrate in this embodiment is in a bottom gate configuration and comprises a plurality of gate lines 11, a plurality of data lines 12, a plurality of pixel electrodes and a plurality of thin film transistors, which are all formed on a substrate 1. The thin film transistor is a bottom gate type transistor. A plurality of pixel regions are defined by intersecting the gate lines 11 and the data lines 12 perpendicular to each other. In each of the pixel regions, one thin film transistor serving as switch element and one pixel electrode 9 are provided. The gate lines 11 are used to supply the turn-on signals to the thin film transistors, and the data lines 12 are used to supply the data signals to the pixel electrodes 9. The gate electrodes of the thin film transistors are formed by a transparent conductive film with a small thickness. For example, the thickness of the transparent conductive film is 300-600 Å. Because the gate electrodes are formed by the transparent conductive film and the transparent conductive film has a small thickness (such as 300-600 Å) as described above, both the variation of the inclination angles of side surface among the gate electrodes and that of the areas occupied by the gate electrode side surfaces can be decreased, thus the influence of the inclination angle of side surface of each gate electrode on the overlapping area between the gate electrode and the corresponding drain electrode can be decreased. Therefore, the variation of the parasitic capacitance of the thin film transistors at different positions over the array substrate can be decreased, and accordingly the variation of the kickback voltages ΔVp among the thin film transistor can also be decreased.