Thin film transistor substrate and display using the same

Provided are a thin film transistor substrate and a display using the same. A thin film transistor substrate includes: a substrate, a first thin film transistor disposed at a first area of the substrate, the first thin film transistor including: a polycrystalline semiconductor layer, a first gate electrode on the polycrystalline semiconductor layer, a first source electrode, and a first drain electrode, a second thin film transistor disposed at a second area of the substrate, the second thin film transistor including: a second gate electrode, an oxide semiconductor layer on the second gate electrode, a second source electrode, and a second drain electrode, a nitride layer disposed on an area of the substrate, other than the second area, the nitride layer covering the first gate electrode, and an oxide layer disposed: over the first gate electrode and the second gate electrode, and under the oxide semiconductor layer.