A Thin Film Transistor (TFT) that can reduce leakage current and can prevent crosstalk between adjacent TFTs includes: a substrate; a gate electrode disposed on the substrate; a source electrode and a drain electrode separated from each other and insulated from the gate electrode; and a semiconductor layer which is insulated from the gate electrode, contacts each of the source and drain electrodes, and has grooves that separate at least a region of the semiconductor layer between the source and drain electrodes from the adjacent TFT. Each groove passes at least a portion of the semiconductor layer corresponding to the source and drain electrodes, and a projection image generated when each groove that passes at least a portion of the semiconductor layer corresponding to the source and drain electrodes is projected onto the source and drain electrodes covers the source and drain electrodes except for a portion of the source electrode that faces the drain electrode and a portion of the drain electrode that faces the source electrode.