Electrical properties and modeling of ultrathin impurity-doped silicon dioxides

The electrical properties of silicon dioxides doped with impurities (fluori ne and/or nitrogen) are investigated in this article. Pure silicon dioxide (SiO2), fluorine-doped silicon oxide (SiOF), nitrogen-doped silicon oxide ( SiON), and nitrogen-doped SiOF (SiOFN) are our choices for investigation in this study. The oxide films are prepared from liquid-phase-deposited fluor inated silicon oxides under O-2 or N2O annealing. The leakage current as a function of applied voltage for impurity-doped oxides was simulated using a generalized trap-assisted tunneling (GTAT) model at moderate fields of 5-8 MV/cm. Two important parameters, trap energy level Phi (t) and trap concen tration N-t, are directly derived by this model from simple current-voltage characteristics. The relationships of Phi (t) and N-t on various experimen tal conditions (annealing temperature, time, gases, and initial oxide thick ness) are comprehensively studied based on GTAT modelings. (C) 2001 America n Institute of Physics.