Properties of HfO2/Hf-silicate/Si structures with Hf-silicate formed by Hfmetal deposition and subsequent reaction

Properties of the HfO2/Hf-silicate/Si structure with the Hf-silicate layer which was formed by Hf metal deposition On Si and subsequent reaction of Hf with Si and oxygen during the HfO2 deposition were studied. Post-depositio n N-2 annealing reduced the equivalent oxide thickness (EOT) value and impr oved leakage characteristics Of the HfO2/Hf-silicate/Si structure. The EOT value was reduced from 2.70 nm to 2.23 nm after annealing. At a proper volt age of 2.5 V, which was defined as the difference between the applied gate bias and the flat band voltage, the leakage current density of annealed HfO 2/Hf-silicate/Si structure was 1.88 x 10(-7) A/cm(2) while that of as-forme d HfO2/Hf-silicate/Si structure was 1.92 x 10(-6) A/cm(2). The breakdown fi eld increased from 7.29 MV/cm to 9.71 MV/cm after annealing.