A display device and method of fabricating the same are provided. The display device includes a substrate and a thin-film transistor formed on the substrate. The thin-film transistor includes a lower gate conductive layer disposed on the substrate, and a lower gate insulating film disposed on the lower gate conductive layer The lower gate insulating film includes an upper surface and sidewalls. The thin-film transistor includes an active layer disposed on the upper surface of the lower gate insulating film, the active layer including sidewalls. At least one of the sidewalls of the lower gate insulating film and at least one of the sidewalls of the active layer are aligned with each other.