Leakage current in HfO2 stacks: from physical to compact modeling

In this paper we discuss the physical mechanisms governing the charge transport inside hafnium based dielectric stack from a modeling perspective. We propose a detailed Monte-Carlo physical model, which describes the charge transport across high-k stacks through the multiphonon trap-assisted-tunneling theory. This model reproduces accurately the voltage and temperature dependencies of the leakage current across HfO2-based stacks. Starting from this physical description, we develop an analytical model for the TAT current across high-k stacks, which can be implemented into SPICE-like circuit simulators. Despite the simplifying approximations, this compact model reproduces accurately the measurements, thus representing an effective tool for the investigation of the TAT currents.