Patent ID: 7629189

Claim:
A method of fabricating a liquid crystal display device, comprising: forming a first conductive pattern group including a gate line and a gate electrode connected to the gate line on a lower substrate using a first mask; forming a gate insulating film covering the first conductive pattern group; forming a semiconductor pattern having an active layer and an ohmic contact layer, and a second conductive pattern group including a data line overlapped with the semiconductor pattern and a source-drain metal pattern overlapped with the semiconductor pattern on the gate insulating film using a second mask; forming a protective film including a first contact hole covering the semiconductor pattern and the second conductive pattern group, and exposing a portion of the source-drain metal pattern using a third mask; and separating a source electrode and a drain electrode from the source-drain metal pattern after forming the protective film, forming a channel portion between the source electrode and the drain electrode, and forming a pixel electrode covering the first contact hole using a fourth mask, wherein the fourth mask includes a transmitting area, a shielding area, and a partial transmitting area, wherein a step of using the fourth mask includes: sequentially disposing a transparent conductive film and a photo-resist on the protective film; forming a first photo-resist pattern at a portion corresponding to the shielding area, and a second photo-resist pattern having a height substantially lower than a first photo-resist pattern at a portion corresponding to the partial transmitting area by the exposure process and the development process; etching the transparent conductive film exposed by the first and second photo-resist patterns to expose the protective film; etching the exposed protective film, the source-drain metal pattern provided at a lower portion of the exposed protective film, and an ohmic contact layer to expose the active layer; ashing the first and second photo-resist patterns using a plasma gas to remove the second photo-resist pattern, and to expose the transparent conductive film; etching the exposed transparent conductive film to pattern; and stripping the first photo-resist pattern, wherein a channel protective film is formed at an upper portion of the exposed active layer by an ashing process using the plasma gas.