Electronic processes in silicon nitride

Time, electric field, and temperature dependence of the flat-band voltage shift and steady-state contact-current versus contact-field characteristics in polycrystalline silicon-oxide-nitride-oxide-silicon structures subjected to high field stress have been studied in detail. Experimental data are compared with exact (numerical) solutions of the Arnett model [P. C. Arnett, J. Appl. Phys. 46, 5236 (1975)] for one-carrier (electron) transport in silicon nitride. It is shown that a simple field-assisted thermal ionization (Poole–Frenkel) detrapping mechanism cannot explain the experimental observations, leading to unphysical values for the attempt-to-escape frequency. An alternative model is proposed based on a thermally assisted tunneling detrapping mechanism. Trap density, effective capture cross section, ground-state energy, and an upper limit for the energy of the first excited state of the electron trap are determined.