Patent ID: 8629448

Claim:
A flat panel display device, comprising: a substrate, the substrate including a first region and a second region; an active layer on the first region of the substrate, the active layer including a semiconductor material; a lower electrode on the second region of the substrate, the lower electrode 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, the gate electrode 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, the upper electrode 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, the second insulating layer 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, wherein: the second conductive layer pattern corresponding to the upper electrode includes an opening exposing a portion of the first conductive layer pattern therethrough, and the lower electrode corresponding to the opening includes dopant ions.