Temperature-dependent low electric field charging of Si nanocrystals embedded withinoxide–nitride–oxide dielectric stacks

Abstract

In this work we examine the current peaks and the negative differential resistance thatappear in the low electric field regime of oxide–nitride–oxide structures with atwo-dimensional band of silicon nanocrystals embedded in a nitride layer. Thesilicon nanocrystals were synthesized by low energy ion implantation (1 keV,1.5 × 1016 Si+ cm−2) and subsequentthermal annealing (950 °C, 30 min). Electrical examination was performed at temperatures from 20 to100 °C using constant voltage ramp-rate current measurements. This approach enablesus to determine the origin of the observed current peaks as well as to extractthe trapping location of the injected carriers within the dielectric stack. Theresults confirm that the carriers are trapped within the Si nanocrystal band,verifying that this region corresponds to energy minima of the dielectric stack.