This study proposes a novel HfO2 nanocrystal memory on epi-SiGe (Ge: 15%) channel. Because SiGe has a smaller bandgap than that of silicon, it increases electron/hole injection and the enhances program/erase speeds. This study compares the characteristics of HfO2 nanocrystal memories with different oxynitride tunnel oxide thicknesses on Si and epi-SiGe substrate. Results show that the proposed nonvolatile memory possesses superior characteristics in terms of considerably large memory window for two-bits operation, high speed program/erase for low power applications, long retention time, excellent endurance, and strong immunity to disturbance. (C) 2012 Elsevier Ltd. All rights reserved.