Injection Mechanisms and Lifetime Prediction with the Substrate Voltage in 0.15μm Channel-Length N-MOSFETs

International audience; The effects of the substrate voltage are studied in advanced N-MOSFETs with a 3.2m gate-oxide thickness used for logic applications. Results show that the electronic gate current originates at low voltage from tunneling contributions and from the first-induced second impact ionization mechanisms. The injection efficiency is found to be channel-length dependent through a large increase in the gate-current with the increase in the lateral field (vertical field) and the electron-electron scattering for low-energy hot-carriers. Lifetime prediction techniques are compared showing a strong device lifetime reduction with the back bias at VSB = VDD independently of the extrapolating model which can be modeled by the measurement of the gate-current and the emission probability.