METHOD FOR MANUFACTURING TFT

摘要

PURPOSE: A method for manufacturing a TFT(Thin Film Transistor) is provided to prevent the generation of splashes by performing uniform etching through improved 4-mask process and uniformly forming a critical dimension for metallization. CONSTITUTION: A TFT is manufactured by using 4-mask process. While a gate is formed, an insulating film, a semiconductor layer, an extrinsic semiconductor layer, a source/drain layer, and a photoresist film are layered sequentially. The photoresist film is exposed by using a mask patterned depending on a channel area. The source/drain layer is etched through wet etching to the fully exposed area. The extrinsic semiconductor layer and the semiconductor layer are etched through dry etching sequentially. An oxide film is formed on the photoresist film in the exposed area and the non-exposed area. The photoresist film in the exposed area is removed through ashing process. In the exposed source/drain layer, the extrinsic semiconductor layer is exposed by dry etching. The semiconductor layer is exposed by dry etching the exposed extrinsic semiconductor layer.