Electric performance of AlGaN/GaN heterojunction devices: A full-quantum study

Abstract

In this contribution a full-quantum simulation of the electron transport in the two-dimensional electron gas (2DEG) of a AlGaN/GaN heterostructure is carried out using the non-equilibrium Green function (NEGF) approach. Even if electrical and mechanical properties of a AlGaN/GaN heterojunction are now well understood, a host of techniques like thinning of layers as in gate recess, use of advance materials like high-k dielectrics, introduction of back-barriers or channel interfaces, are considerably intricating the physical modeling of the heterojunction and precise simulations that correctly take into account for physical effects at the nano-scale are deemed necessary. In this study the quantum-mechanical effects in the electron transport layer properties are accounted for both in the quantization and in the transport direction. First, we focus in particular to a comparative study of the threshold voltage formation. We then we address the gate scaling, identifying the channel length at which short-channel-effects may be nonnegligible any more.