Study of reliability degradation in power RF LDMOS under pulsed life test due to impact ionization

摘要

This paper explained that an electric field is an accelerating factor of degradation hot carriers' creation. The impact ionization phenomena in the case of NMOSFET is analyzed and, above all, one of its corollaries, the impact ionization of hot carriers. The effects study of hot carriers on the NMOS is a good basis for understanding this phenomenon. Based on RF parameter shifts the reliability of different tests was compared. The constraints impact applied in terms of RF state degradations of the power amplifier is highlighted. Physical simulation has shown that the impact ionization phenomenon plays a role in the generation mechanism of interface states by hot carriers (SiO2 / N-LDD region), which would explain why at 10° C, the degradation amounts on several electrical parameters are also significant. Finally, an analysis of the reliability of radio frequency behavior was discussed.