The band offsets and charge storage characteristics of atomic layer deposited high-k HfO2∕TiO2 multilayers with ten periods in p-Si∕SiO2∕(HfO2∕TiO2)∕Al2O3 structure have been investigated. The thickness of high-k HfO2 or TiO2 film is ∼0.5nm for each layer, before and after annealing treatment of 900°C for 1min in N2 ambient. High-resolution transmission electron microscopy, x-ray photoelectron spectroscopy, and ultraviolet photoelectron spectroscopy measurements on high-k HfO2∕TiO2 multilayers confirm the layer-by-layer structure after annealing treatment, suggesting the HfO2∕TiO2 multilayer quantum wells. The valence band offsets of HfO2 and TiO2 films are found to be ∼3.1 and ∼1.5eV, respectively. The conduction band offsets are found to be ∼1.7eV for HfO2 films and ∼0.9eV for TiO2 films. The high-k HfO2∕TiO2 multilayers in p-Si∕SiO2∕(HfO2∕TiO2)∕Al2O3/aluminum memory capacitor show a large capacitance-voltage hysteresis memory window of ∼5V at gate voltage of ±5V, due to the charge storage in multilayer quantum wells. The hysteresis memory window of ∼1.3V at small gate voltage of ±1V is also observed. The high-k HfO2∕TiO2 multilayer memory structure can be used in future nanoscale flash memory device applications.
No takes yet. Share an insight, caveat, or question.
Maikap et al. (2007) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: