Magnetoresistance mobility extraction on TiN∕HfO2∕SiO2 metal-oxide-semiconductor field effect transistors

The impact of a high-κ material on the carrier mobility in n-channel transistors is studied by magnetoresistance measurements. The mobility is extracted on HfO2∕TiN metal-oxide-semiconductor field effect transistors with this innovative technique. Unlike the CV-split technique, the authors have shown that the measurement of the magnetoresistance allows a reliable mobility extraction down to very low carrier density. They have demonstrated that the use of a hafnium-based oxide as a gate dielectric leads to an additional Coulomb scattering term, well identified at low electron density. These experimental results bring further evidence that the mobility degradation is caused by charges in the HfO2 layer as suggested in previous studies.