Device Characterization of Dy-incorporated Hfo2 Gate Oxide Nmos Device: Device Characteristics and Reliability of Dyo / Hfo Gate Dielectrics and the Application to Nand Flash Memory

Dy-incorporated HfO2 gate oxide with TaN gate electrode nMOS device has been developed for high performance CMOS applications in 22nm node technology. This DyO/HfO gate dielectrics shows the thin EOT with reduced leakage current compared to HfO2. Excellent electrical performances of the DyO/HfO gate oxide n-MOSFET such as lower VTH, higher drive current, and improved channel electron mobility are demonstrated. DyO/HfO sample also shows a better immunity for VTH instability and less severe charge trapping characteristics. Its charge trapping characteristics such as SILC and PBTI, VTH shift mechanism by Dy incorporation and dielectric reliability have been intensively investigated with a band diagram and proper models in this work. As an application of the characterization to NAND Flash memory device, HfON charge-trap layered NAND Flash memory is developed for high performance memory device and its reliability issues including the endurance and retention are discussed.