A methodology to simulate memory structures with metal nanocrystal islands embedded as floating gate in a high-kappa dielectric material for simultaneous enhancement of programming speed and retention time is presented. The computational concept is based on a model for charge transport in nano-scaled structures presented earlier, where quantum mechanical tunneling is defined through the wave impedance that is analogous to the transmission line theory. The effects of substrate-tunneldielectric conduction band offset and metal work function on the tunneling current that determines the programming speed and retention time is demonstrated. Simulation results confirm that a high-kappa dielectric material can increase programming current due to its lower conduction band offset with the substrate and also can be effectively integrated with suitable embedded metal nanocrystals having high work function for efficient data retention. A nano-memory cell designed with silver (Ag) nanocrystals embedded in Al2O3 has been compared with similar structure consisting of Si nanocrystals in SiO2 to validate the concept. (C) 2008 Elsevier Ltd. All rights reserved.