10:30 AM - 10:45 AM
▲ [14a-B7-1] [Young Scientist Presentation Award Speech] Investigation of Bilayer HfN Gate Insulator Formed by ECR Plasma Sputtering
Keywords:Bilayer, Hafnium nitride, ECR plasma sputtering
We investigated the effects of PMA process on the performance of nMISFET with bilayer HfNx gate insulator utilizing ECR plasma sputtering. By using the combination of PMA1 (before Al deposition) at 500°C/1 min with PMA2 (after Al deposition) at 300°C/30 min in N2/4.9%H2 forming-gas ambient, the EOT of 0.55 nm, leakage current density (@VFB -1V) of 6.6x10-5 A/cm2 and density of interface states (Dit) of 5.6x1010 cm-2eV-1 were obtained. The saturation mobility has increased from 47 to 81 cm2/(Vs) compared to the device fabricated with PMA1 at 500°C/10 min. Therefore, the combination of PMA1 and PMA2 processes in N2/4.9%H2 ambient showed the suppression of hysteresis width in C-V from 184 to 54 mV, which leads to the improvement of the nMISFET characteristics.