A liquid crystal display device and a fabricating method thereof for securing aperture ratio are disclosed. In the liquid crystal display device, a gate line is formed. A data line crosses the gate line. A thin film transistor is provided at an intersection of the gate line and the data line. A semiconductor pattern is overlapped with the data line under the data line, and includes an active layer of the thin film transistor. A step coverage does not exist between an etched edge surface of the semiconductor pattern disposed at a lower portion of the data line and an etched edge surface of the data line.