Metal oxide thin films have been used in a wide range of electronic and optoelectronic devices. In this paper, the author discusses his groups recent work on applying the same amorphous Zr-doped HfO2 high-
kthin film to MOS gate dielectrics, nonvolatile memories, and light emitting devices. For each type of device, the operation principle, material requirements, and reliability are discussed. A generalized curve of the stress voltage vs. leakage current density, which includes all operation ranges of the above devices, is presented. It is expected that the same principles is applicable to other metal oxide dielectrics for the similar functions.