Al/La2O3 Analysis of Post Metallization Annealed MISFET by XPS

La2O3 gated MISFETs with various heat treatments were fabricated and measured. High effective mobility was obtained using a Post Metallization Anneal (PMA) with Al gate electrodes. XPS analysis showed the formation of a thin Al2O3 interface layer between the Al and La2O3 during the annealing. The formation of the Al2O3 layer increased the EOT and shifted the flatband shift in the positive direction. The improvement of the effective mobility can be explained by less formation of oxygen vacancies.