Modeling Temperature Dependency (6 - 400K) of the Leakage Current Through the SiO2/High-K Stacks

We investigate the mechanism of the gate leakagecurrent in the Si/SiO2/HfO2/TiN stacks in a wide temperaturerange (6 – 400 K) by simulating the electron transport using amulti-phonon trap assisted tunneling model. Good agreementbetween simulations and measurements allows indentifying thedominant physical processes controlling the temperaturedependency of the gate current. In depletion/weak inversion, thecurrent is limited by the supply of carrier. In strong inversion,the electron-phonon interaction is found to be the dominantfactor determining the current voltage and temperaturedependencies. These simulations allowed to extract importantdefect parameters, e.g. the trap relaxation energy and phononeffective energy, which defines the defect atomic structure.