Memory Characteristics of Atomic-Layer-Deposited High-κ HfAlO Nanocrystal Capacitors

The memory characteristics of atomic-layer-deposited high-κ HfAlO nanocrystals in a p - Si ∕ SiO 2 ∕ [ HfO 2 ∕ Al 2 O 3 ] ∕ Al 2 O 3 /platinum structure have been investigated. After the annealing treatment, the high-κ HfAlO nanocrystals with a small diameter of < 10 nm and high density of 5 × 10 11 cm 2 have been observed by high-resolution transmission electron microscopy. A large hysteresis memory window of ∼ 10.4 V has been obtained. The high-κ HfAlO nanocrystal memory capacitor with a small capacitance equivalent thickness of ∼ 8.5 ± 0.5 nm shows a small leakage current density of ∼ 22 μ A cm 2 at a gate voltage of − 16 V . A large memory window of ∼ 8 V has also been observed after 10 5 s of retention, due to the charge confinement in the high-κ HfAlO multilayer nanocrystals.