La Al O 3 gate dielectric with ultrathin equivalent oxide thickness and ultralow leakage current directly deposited on Si substrate

By a careful choice of film deposition conditions, LaAlO3 (LAO) gate dielectric film with equivalent oxide thickness (EOT) of 0.31nm and gate leakage current density (Jg) of 0.1A∕cm2 (at Vfb+1V) has been successfully demonstrated. Elimination of interfacial low-k layer at LAO/Si and reduction of defect density in LAO has been realized through both LAO film deposition at high-temperature (700°C) and subsequent low-temperature (200°C) annealing. By using thermal desorption spectroscopy technique, we find that our process reduces remnant H2O or OH− species in the LAO film, which are responsible for the degradation of EOT and Jg.