Patent ID: 8110830

Claim:
A method of manufacturing a TFT array substrate, comprising: forming a gate line layer including a gate line, a gate electrode, and a gate pad on a substrate; forming a gate insulation film on the front surface of the substrate including the gate line layer; forming a semiconductor layer overlapping with the gate electrode; forming a data line layer including a data line intersecting the gate line, source and drain electrodes disposed at opposite sides of the semiconductor layer, and a data pad formed at the end of the data line; forming an at least two-layered passivation film on the front surface of the substrate including the data line layer; forming a photoresist pattern on the uppermost layer of the at least two-layered passivation film; selectively etching the at least two-layered passivation film using the photoresist pattern as a mask to form a contact hole and first and second opening regions and, at the same time, excessively etching the uppermost layer of the at least two-layered passivation film below the photoresist pattern in the horizontal direction; depositing a conductive material on the front surface of the substrate including the photoresist; and patterning the conductive material by lifting off the photoresist to form a pixel electrode contacting the drain electrode through the contact hole and first and second oxidation preventing films contacting the gate pad and the data pad through the first and second opening regions, wherein the step of forming the at least two-layered passivation film includes sequentially depositing first to third passivation films to cover the data line layer, and the step of forming the contact hole and the first and second opening regions and excessively etching the uppermost layer of the at least two-layered passivation film below the photoresist pattern in the horizontal direction includes etching the third passivation film through a dry etching process, ashing the second passivation film through an ashing process, and etching the first passivation film through a wet etching process.