A flat panel display device including a substrate including first and second regions; an active layer on the first region of the substrate including a semiconductor material; a lower electrode on the second region of the substrate including the semiconductor material; a first insulating layer on the substrate including the active layer and the lower electrode thereon; a gate electrode on the first insulating layer overlying the active layer and including a first conductive layer pattern and a second conductive layer pattern; an upper electrode on the first insulating layer overlying the lower electrode and including the first conductive layer pattern and the second conductive layer pattern; a second insulating layer on the gate electrode and the upper electrode exposing portions of the active layer and portions of the upper electrode; and a source electrode and a drain electrode connected to the exposed portions of the active layer.