Multiphonon ionization of traps formed in hafnium oxide by electrical stress

We have investigated behavior of traps formed in hafnium oxide (HfO ₂) by electrical stress and their influence on the charge carrier transport through Si/SiO₂/HfO₂/poly-Si nanostructures. The traps govern the transport process assuming a capture of charge carriers followed by their ionization via the multiphonon transition mechanism. The multiphonon transitions via the Poole-Frenkel effect or electron tunneling as well as the multiphonon tunneling ionization of neutral traps have been carefully considered for charged traps. We also provide a set of parameters including the trap concentration, ionization energy, the frequency factor, the effective mass of charge carriers, optical energy, and phonon energy in order to reproduce and reasonably fit available experimental data.