AbstractIn this work, we examine the influence of hafnium and zirconium oxides ALD precursor chemistry on the memory properties of SiO2/Si3N4/ZrO2 and SiO2/Si3N4/HfO2 non-volatile gate memory stacks. Approximately 10 nm thick ZrO2 and HfO2 layers were deposited on top of a SiO2/Si3N4 structure, functioning as blocking oxides. Both metal oxides were deposited using either alkylamides or cyclopentadienyls as metal precursors, and ozone as the oxygen source. In the case of the ZrO2 gate stacks a memory window of 6 V was determined, comprised of 4 V write window and 2 V erase window. Although no dramatic differences were evident between the ZrO2 layers, ZrO2 grown from alkylamide provided structures with higher dielectric strength. The memory structures with HfO2 blocking layers indicate that the memory window and the dielectric strength are significantly affected by the precursor. The structures with the HfO2 formed from alkylamide showed a write window of 7 V, while the films grown from cyclopentadienyl possessed window of 5 V. Comparison between the memory windows obtained using ZrO2 and HfO2 as control oxides reveals that the former provides memory structures with higher electron trapping efficiency.
