Bias dependence of PBTI degradation mechanism in metal-oxide-semiconductor field effect transistors with La-incorporated hafnium-based dielectric

Metal-oxide-semiconductor field effect transistors (MOSFETs) with various concentrations of La incorporated in Hf-based dielectrics were characterized to evaluate the effect of La on devices' reliability. Compared with the small dependence of positive bias stress instability (PBTI) on stress bias in samples without La incorporation, significant dependence of PBTI degradation on stress bias was observed in the La-incorporated samples. HRTEM analysis and flat band voltage modulation data supported the interface dipole model, suggesting that this bias dependence of PBTI degradation in the La-incorporated samples could be explained by changes of electron tunneling mechanism due to interface dipoles.