The phenomenon of white light emission from solid state incandescent light emitting devices made of Zr-doped HfO2 high-
kdielectric stacks under the O2 or N2 post deposition annealing condition has been investigated. Compared with the N2 annealed sample, the O2 annealed sample had different properties: 1) a SiOx-like interface layer, 2) lower defect densities in bulk and interface layers, 3) a larger dielectric breakdown voltage, 4) a low leakage current, 5) fewer light emission dots, and 6) stronger emitted light. The shape of the emitted light and other optical properties were little influenced by the annealing gas. The high temperature of the conductive path during the operation enhanced the diffusion of Si to the gate electrode and Zr to the high- k/Si interface. This kind of device is applicable to a wide range of areas.