HfO₂/HfAlO/HfO₂ nanolaminate charge trapping layers for high-performance nonvolatile memory device applications

A high-κ HfO₂/HfAlO/HfO₂ nanolaminate charge trapping layer in a p-Si/SiO₂/[HfO₂/HfAlO/HfO₂ nanolaminate]/Al₂O₃/ platinum memory capacitor has been investigated. High-κ HfO₂, Al₂O₃, and HfO₂/HfAlO/HfO₂ nanolaminate charge trapping layers are deposited by atomic layer deposition. Well-behaved counter clockwise capacitance-voltage hysteresis characteristics are observed for all memory capacitors. A large memory window of ∼10 V, a very low leakage current density of ∼5 × 10^-9 A/cm² at a gate voltage of -5 V, a high charge trapping density of ∼1.6 × 10¹³/cm ², and a low charge loss of ∼20% after 10 years of retention for the HfO₂/HfAlO/HfO₂ nanolaminate charge trapping layer are observed as compared with those of pure HfO₂ and pure Al ₂O₃ charge trapping layers. Excellent memory characteristics of HfO₂/HfAlO/HfO₂ nanolaminate layers are obtained owing to the layer-by-layer charge storage. High-κ HfO ₂/HfAlO/HfO₂ nanolaminate charge trapping layers can be used in future nanoscaled high-performance nonvolatile memory device applications.