Charge Storage Characteristics of Silicon Nanoclusters in Silicon Nitride Matrix Grown by Laser Assisted Chemical Vapor Deposition Method

The capacitance–voltage (C–V) and charge retention characteristics of the metal-insulator-semiconductor (MIS) structure, in which the insulator layer was composed of silicon nanocluster-embedded silicon nitride, were studied. The memory effect of this MIS structure was dominantly attributed to the charge storage in the silicon nanoclusters. The relation between the flatband voltage shift and the amount of charges stored in the nanocluster-embedded insulator layer was discussed. The capacitance–time (C–t) relation of MIS structures, conventionally used to follow the discharge process, was further analyzed, indicating that care should be taken in the C–t measurement for obtaining correct discharging behavior. Then the charge retention characteristics of the fabricated MIS structures under various charging conditions were derived by the capacitance–time (C–t) measurement. The results showed that the devices, charged for a longer time or under a lower charging voltage, discharge slower. The observed charge retention behaviors can be reasonably attributed to the spatial distribution of silicon nanoclusters in the silicon nitride layer and the dispersion of the nanocluster sizes