Memristor structure with the effect of switching resistance based on silicon nitride thin layers

Abstract

The electrophysical properties and the resistive switching effect of the ITO/SiNx/Si memristor structure were studied. A silicon nitride film with a thickness of ~200 nm with an inhomogeneous element depth distribution was deposited by low-pressure chemical vapor deposition. Based on the Rutherford backscattering data, it was shown that the concentration of excess silicon atoms in the SiNx film increases from 9 to 44 % when approaching the Si substrate. The analysis of the current-voltage characteristics of ITO/SiNx/Si structures revealed that the conduction mechanism in the high-resistance state is determined by the nitride film properties and is described by the Poole–Frenkel model taking into account the hopping model of electron transport between traps. Switching to the low-resistance state is probably caused by the migration of indium or tin ions from the ITO contact to the SiNx layer. The conduction of the ITO/SiNx/Si structure in the low-resistance state is determined by both the mechanisms of charge-carrier injection from the contact and charge-carrier transport through the dielectric layer. Reverse polarity results in destructing the conductive channel and switching the structure to the high-resistance state. The photo-switching effect was found for the ITO/SiNx/Si structure, which opens up new possibilities of using memristors in silicon optoelectronic systems.