Electrical characteristics of AlOxNy prepared by oxidation of sub-10-nm-thick AlN films for MOS gate dielectric applications

In this research. the feasibility of ultrathin AlOxNy prepared by oxidation of sub 100-Angstrom -thick AlN thin films for metal-oxide-semiconductor (MOS) gate dielectric applications was investigated. Oxidation of 51-Angstrom -and 98-Angstrom -thick as-deposited AlN at 800 degreesC was used to form 72-Angstrom -and 130-Angstrom -thick AlOxNy, respectively. Based on the capacitance-voltage (C-V) measurements of the MOS capacitor, the dielectric constants of 72 Angstrom -thick and 130 Angstrom -thick Al-oxynitride were 5.15 and 7, respectively. The leakage current of Al-oxynitride at low field was almost the same as that of thermal SiO2. Based on the CV data, the interface state density of Al-oxynitride was relatively higher than that of SiO2. Although process optimization is still necessary, the Al-oxynitride exhibits some possibility for future MOS gate dielectric applications.