Multilayer Ge nanocrystals embedded within Al₂O₃ matrix for high performance floating gate memory devices

Metal-insulator-silicon devices with Ge nanocrystals dispersed in Al₂O₃ have been studied with a view to exploit them for floating gate memory applications. Multilayer devices comprising of five layers Ge nanocrystals have exhibited superior memory characteristics over the single layer Ge and multilayer Si nanocrystals reported in literature. The effect of interface traps on the memory behavior using frequency dependent capacitance- and conductance-voltage measurements has been investigated. This study has demonstrated an enhanced memory window with superior retention characteristics, owing to the Coulomb blockade effect, due to the introduction of multi-layer nanocrystals in the floating gate.