Memory properties of p-Si/ultrathin Al2O3/(HfO2)(0.8)(Al2O3)(0.2)/Al2O3/metal capacitors have been investigated, in which all the high-k dielectric films were derived by atomic layer deposition technique. Using a (HfO2)(0.8)(Al2O3)(0.2) film as the charge trapping layer, a large memory window of 5.7 V and a high charge trap density of 2.4 x 10(13) cm(-2) have been achieved. A 53% initial memory window can still be maintained after 10 years of retention even after adopting an ultrathin tunneling Al2O3 layer of 2 nm. The experimental results also demonstrated that adding Al2O3 into HfO2 films can improve the memory characteristics as compared with the memory capacitors employing pure HfO2 as the charge trapping layer. (c) 2010 The Electrochemical Society. [DOI: 10.1149/1.3518706] All rights reserved.