Large-Signal Modeling of a 50 nm mHEMT Incorporating a Physical Impact-Ionization Model

In this paper, investigations on the gate-current of 50 nm metamorphic HEMTs (mHEMT) are performed, where evidences on impact ionization are observed. An accurate fit for different device sizes was obtained using a physical model for its induced gate-current, suggesting further indications that the observed phenomena are related to impact ionization. An empirical large-signal model a 50 nm gate-lenght mHEMT incorporating the physical model is presented in this paper.