Modelling of trap-assisted electronic conduction in thin thermally nitrided oxide films

The current-voltage characteristics of thin thermally nitrided oxide films have been investigated in detail at temperatures ranging from 100 to 298 K. Considering the fact that shallow traps do not capture any electrons but contribute to the current conduction, a trap-assisted conduction model for dielectric films is developed. The theoretical results are in good agreement with the experimental data. For electric fields in the range of 6-8 MV cm(-1), we found that at room temperature the transport current in the nitrided oxide is governed mainly by shallow trap-assisted tunnelling, and by deep trap-assisted tunnelling at low temperatures (<150 K). The energy level of shallow traps is found to be between 0.033 and 0.118 eV, while the deep trap levels are between 2.89 and 3.08 eV.