Study of an AlSi3N4 interface by photoinjection measurements in MNS and MNOS sandwiches

From photoinjection measurements of an Al/Si₃N₄/SiO₂/Si structure, a mechanism is proposed for the charging process of the traps situated in the insulator close to the metallic emitter electrode. A decomposition of the evolution of the barrier in two steps, increase in the barrier height and drift of the position of the barrier maximum, is shown and correlated with spatial depth of filling of the traps in the insulator. A method is deduced for determining the zero field barrier height of the AlSi₃N₄ interface when a trapped space charge prevents the use of the conventional method, and a value for the scattering mean free path of electrons in Si₃N₄ is obtained.