LaAlO3 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 0.31 nm and gate leakage current density (J(g)) of 0.1 A/cm(2) (at V-fb+1 V) 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 degrees C) and subsequent low-temperature (200 degrees 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 J(g). (c) 2008 American Institute of Physics.