Thin film transistor array substrate for liquid crystal display and method for fabricating the same

Abstract

In a method of fabricating a thin film transistor array substrate, a black matrix with horizontal and vertical portions is first formed on a substrate with an opaque conductive material. A gate line assembly is formed on the black matrix, and buffer layers are formed between the separate portions of the black matrix. A gate insulating layer, a semiconductor layer, and an ohmic contact layer are sequentially deposited onto the substrate. And a data line assembly is formed on the ohmic contact layer. The ohmic contact layer exposed through the data line assembly is etched, and a protective layer is deposited onto the substrate. The protective layer, the gate insulating layer, and the semiconductor layer are patterned to form contact holes and opening portions exposing the insulating layer at pixel areas. The peripheral portions of the black matrix are also exposed through the opening portions. An indium tin oxide layer is deposited onto the substrate, and patterned to form pixel electrodes, subsidiary gate pads and subsidiary data pads that are connected to the drain electrodes, the gate pads and the data pads through the contact holes. Buffer conductive layers are formed at the same plane as the data line assembly or the pixel electrodes while being positioned over the semiconductor pattern between the neighboring data lines. Opening portions may be formed at a common electrode of the color filter substrate over the semiconductor pattern.

Description

BACKGROUND OF THE INVENTION [0001] (a) Field of the Invention [0002] The present invention relates to a thin film transistor (TFT) array substrate for liquid crystal displays and a method for fabricating the same and, more particularly, to a TFT array substrate of good performance characteristics. [0003] (b) Description of the Related Art [0004] Generally, a liquid crystal display (LCD) is formed with two glass substrates, and a liquid crystal sandwiched in-between the substrates. [0005] One of the substrates has a common electrode, a color filter and a black matrix, and the other substrate has pixel electrodes and thin film transistors (TFTs). The former substrate is usally called the “color filter substrate,” and the latter substrate called the “TFT array substrate.”[0006] The TFT array substrate is fabricated through forming a plurality of thin films, and performing photolithography with respect to the thin films. In photolithograpy, a number of masks are used for uniformly etchi...

AI Technical Summary

Benefits of technology

"The present invention provides a method for fabricating a TFT array substrate for a LCD with reduced number of masks and simplified processing steps. Additionally, the invention provides a method for increasing the device opening ratio of the TFT array substrate. The technical effects of the invention include reducing the number of masks required for the fabrication process and improving the device opening ratio."

Problems solved by technology

In photolithograpy, a number of masks are used for uniformly etching the thin films, involving complicated processing steps and increased production cost.

However, the wider black matrix reduces the opening ratio.

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