Improved device performance and reliability in high κ HfTaTiO gate dielectric with TaN gate electrode

The device performance and reliability of higher-κ HfTaTiO gate dielectrics have been investigated in this letter. HfTaTiO dielectrics have been reported to have a high-κ value of 56 and acceptable barrier height relative to Si (1.0 eV). Through process optimization, an ultrathin equivalent oxide thickness (EOT) (∼9 Å) has been achieved. HfTaTiO nMOSFET characteristics have been studied as well. The peak mobility of HfTaTiO is 50% higher than that of HfO₂ and its high field mobility is comparable to that of HfSiON with an intentionally grown SiO₂ interface, indicative of superior quality of the interface and bulk dielectric. In addition, HfTaTiO dielectric has a reduced stress-induced leakage current (SILC) and improved breakdown voltage compared to HfO₂ dielectric.