NiSi nanocrystals of high density and good uniformity were synthesized by vapor-solid-solid growth in a gas source molecular beam epitaxy system using Si2H6 as Si precursor and Ni as catalyst. A metal-oxide-semiconductor memory device with NiSi nanocrystal-Al2O3/SiO2 double-barrier structure was fabricated. Large memory window and excellent retention at both room temperature and high temperature of 85 degrees C were demonstrated. (C) 2011 Elsevier Ltd. All rights reserved.