Patent ID: RE41632

Claim:
A method of manufacturing a liquid crystal display device, comprising: a first photolithography process forming a gate electrode on a substrate; a second photolithography process including: a) depositing sequentially a gate insulating layer, a semiconductor layer, and a metal layer; b) applying a first photoresist on the metal layer; c) aligning a first photo mask with the substrate; d) light exposing and developing the first photoresist to produce a first photoresist pattern; e) etching the metal layer using a first etchant, the first etchant ashing the first photoresist pattern on a portion of the metal layer to produce a second photoresist pattern, thereby exposing the portion of the metal layer; and f) etching the gate insulating layer, the semiconductor layer, and the portion of the metal layer using a second etchant according to the second photoresist pattern to form source and drain electrodes, an ohmic contact layer, and an active area; a third photolithography process forming a passivation film and a contact hole; and a fourth photolithography process forming a pixel electrode connecting with the drain electrode through the contact hole.