A thin film transistor (TFT), including a crystalline semiconductor pattern on a substrate, a gate insulating layer on the crystalline semiconductor pattern, the gate insulating layer having two first source/drain contact holes and a semiconductor pattern access hole therein, a gate electrode on the gate insulating layer, the gate electrode being between the two first source/drain contact holes, an interlayer insulating layer covering the gate electrode, the interlayer insulating layer having two second source/drain contact holes therein, and source and drain electrodes on the interlayer insulating layer, each of the source and drain electrodes being insulated from the gate electrode, and having a portion connected to the crystalline semiconductor pattern through the first and second source/drain contact holes.