Electron and hole injection in metal-oxide-nitride-oxide-silicon structures

The kinetics of electron and hole accumulation in metal-oxide-nitride-oxide-semiconductor structures is studied. Experimental data are compared with a theoretical model that takes into account tunnel injection, electron and hole capture by traps in amorphous silicon nitride SiNx, and trap ionization. Agreement between experimental and calculated data is obtained for the bandgap width E-g = 8.0 eV of amorphous SiO2, which corresponds to the barrier for holes Phi(h) = 3.8 eV at the Si/SiO2 interface. The tunneling effective masses for holes in SiO2 and SiNx are estimated at m(h)* approximate to (0.4-0.5)m(0). The parameters of electron and hole traps in SiNx are determined within the phonon-coupled trap model: the optical energy W-opt = 2.6 eV and the thermal energy W-T = 1. 3 eV.