Memory characteristics of atomic-layer-deposited high-kappa HfAlO nanocrystal capacitors

摘要

The memory characteristics of atomic-layer-deposited high-kappa HfAlO nanocrystals in a p-Si/SiO2/[HfO2/Al2O3]/Al2O3/platinum structure have been investigated. After the annealing treatment, the high-kappa HfAlO nanocrystals with a small diameter of < 10 nm and high density of > 5 x 10(11) cm(2) have been observed by high-resolution transmission electron microscopy. A large hysteresis memory window of similar to 10.4 V has been obtained. The high-kappa HfAlO nanocrystal memory capacitor with a small capacitance equivalent thickness of similar to 8.5 +/- 0.5 nm shows a small leakage current density of similar to 22 mu A cm(2) at a gate voltage of -16 V. A large memory window of similar to 8 V has also been observed after 10(5) s of retention, due to the charge confinement in the high-kappa HfAlO multilayer nanocrystals. (C) 2008 The Electrochemical Society.