Performance of nonvolatile memory by using band-engineered SrTiO 3/HfON stack as charge-trapping layer

Abstract

The charge-trapping properties of band-engineered SrTiO 3/HfON stack were investigated by using the Al/Al 2O 3/SrTiO 3-HfON/SiO 2/Si structure. By adding the HfON layer, the undesirable silicate interlayer due to the reaction of SrTiO 3 with SiO 2 was suppressed as confirmed by X-ray photoelectron spectroscopy, transmission electron microscopy and secondary ion mass spectroscopy. Large memory window (10.6 V at ±12-V sweeping voltage) and high program speed (3.2 V at +12 V for 100 μs) are obtained for this proposed device. Moreover, it exhibits better retention property than another device without the HfON layer (charge loss of 20.0% versus 48.8%) due to suppressed charge-leakage path resulting from the good HfON/SiO 2 interface and band-engineered charge-trapping structure consisting of SrTiO 3 and HfON. © 2012 Elsevier Ltd. All rights reserved.