Abstract: A thin film transistor for a display device includes a substrate, a gate electrode formed on the substrate, a gate insulating layer formed on the gate electrode, a polycrystalline semiconductor formed on the gate insulating layer and overlapping the gate electrode, a source electrode partially overlapping the polycrystalline semiconductor, and a drain electrode partially overlapping the polycrystalline semiconductor. The polycrystalline semiconductor includes a plurality of first polycrystalline semiconductors that are doped with conductive impurities and a plurality of second polycrystalline semiconductors that are not doped with conductive impurities, and the first polycrystalline semiconductors are disposed between and connected in series with adjacent ones of the second polycrystalline semiconductors.

Abstract: A display device and a manufacturing method thereof are provided. The display device includes a substrate, first and second signal lines formed on the substrate, a first thin film transistor connected to the first and second signal lines., a gate driver and a data driver connected to the first signal line and the second signal line, respectively, and a second thin film transistor formed in at least one of the gate driver and the data driver The first thin film transistor and the second thin film transistor include a first semiconductor and a second semiconductor, respectively, and the first semiconductor and the second semiconductor are formed at the different layers from each other.

Abstract: In a metal wiring, a method of forming the metal wiring, a display substrate having the metal wiring and a method of manufacturing the display substrate, the metal wiring includes a metal film and a first amorphous carbon film. The metal film is formed on a base substrate using a copper-containing material, and the first amorphous carbon film is formed beneath the metal film. A process for forming the metal wiring including the amorphous carbon film may be greatly simplified, and generation of defects in the metal wiring may be prevented or reduced.