Electrical properties and modeling of ultrathin impurity-doped silicon dioxides

The electrical properties of silicon dioxides doped with impurities (fluorine 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 fluorinated silicon oxides under O₂ 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 Φ_t and trap concentration N_t, are directly derived by this model from simple current–voltage characteristics. The relationships of Φ_t and N_t on various experimental conditions (annealing temperature, time, gases, and initial oxide thickness) are comprehensively studied based on GTAT modelings. © 2001 American Institute of Physics.