Resistive switching properties of a thin SiO2 layer with CeOx buffer layer on n+ and p+ Si bottom electrodes

Abstract Resistive switching properties of a 2-nm-thick SiO 2 with a CeO x buffer layer on p + and n +  Si bottom electrodes were characterized. The distribution of set voltage (V set ) with the p +  Si bottom electrode devices reveals a Gaussian distribution centered in 4.5 V, which reflects a stochastic nature of the breakdown of the thin SiO 2 . Capacitance–voltage (C–V) measurements indicate the trapping of electrons by positively shifting the C–V curve by 0.2 V during the first switching cycle. On the other hand, devices with the n +  Si bottom electrodes showed a broad distribution in V set with a mean value higher than that of p +  Si bottom electrode devices by 0.9 V. Although no charge trapping was observed with n +  Si bottom electrode devices, a degradation in interface states was confirmed, causing a tail in the lower side of the V set distribution. Based on the above measurements, the difference in the V set can be understood by the work function difference and the contribution of electron trapping.