Parameters extraction of hafnium based gate oxide capacitors

From quantum simulations of both capacitance and current measurements, the main physical parameters (dielectric thickness and permittivity, doping levels) of hafnium based (HfSiOx and HfO2) gate oxide capacitors have been extracted. Three kinds of gates (n+-polysilicon, totally silicided (TOSI) NiSi and metal TiN gates) have been studied. In the case of thick (EOT between 11.1 and 12.3 nm) HfSiOx gate oxides or thin (EOT inferior to 2 nm) HfO2 stacks with n+-polysilicon or TiN gates, a good agreement between simulations and experimental data is obtained. Electron tunneling currents are prevalent in these stacks except for the specific case of TiN/HfO2 stacks in p-substrate accumulation mode. In this case, electron and hole tunneling transparencies become of the same order of magnitude. Hole transport contribution can no more be neglected and should be taken into account in simulations.