A method of fabricating an array substrate for a liquid crystal display device includes: forming an initial photoresist (PR) pattern on a metallic material layer; etching the metallic material layer using the initial PR pattern as an etching mask to form the data line and a metallic material pattern, wherein the initial PR pattern is disposed on the data line; performing a first ashing process onto the initial PR pattern to partially remove the initial PR pattern so as to form a first ashed PR pattern, the first ashed PR pattern having a smaller width and a smaller thickness than the initial PR pattern such that end portions of the data line are exposed by the first ashed PR pattern; etching the intrinsic amorphous silicon layer and the impurity-doped amorphous silicon layer by a first dry-etching process; forming a source electrode and a drain electrode on the substrate.