An organic light emitting diode display device and method of fabricating the device according to an embodiment includes a substrate; an oxide semiconductor layer over the substrate; a planarization layer over the oxide semiconductor layer; an emitting diode over the planarization layer; a passivation layer over the emitting diode; and a hydrogen blocking layer between the planarization layer and the passivation layer to block hydrogen diffusion from the passivation layer to the oxide semiconductor layer.