METHOD FOR FABRICATING THIN FILM TRANSISTOR SUBSTRATE

摘要

PURPOSE: A method for fabricating a thin film transistor substrate is provided to prevent thin film transistors from being damaged due to static electricity. CONSTITUTION: An amorphous silicon layer is formed on a transparent insulating substrate(110) and heat-treated, to form a polysilicon layer. The polysilicon layer is patterned to form the first and second polysilicon patterns. A gate insulating layer(140) is formed on the first and second polysilicon patterns, and the first metal layer for forming a gate line is formed on the gate insulating layer. The first metal layer is selectively etched to expose a portion of the gate insulating layer, which corresponds to the first polysilicon pattern. An N-type impurity is doped into the first polysilicon pattern to form an N-type active layer(151). The first metal layer is selectively etched to expose a portion of the gate insulating layer, which corresponds to the second polysilicon pattern. A P-type impurity is doped into the second polysilicon pattern to form a P-type active layer(152). The first metal layer is selectively etched to form the gate line(121). An insulating material is coated on the gate line and patterned to form an interlevel insulating layer having the first through eighth contact holes that expose the N-type or P-type active layer. A data line is formed on the interlevel insulating layer.