Al2O3/HfO2 MULTILAYER STACKS FOR NONVOLATILE FLASH MEMORY IT-05 APPLICATIONS
Date Issued
2018-09
Author(s)
D. Spassov, A. Paskaleva, T. A. Krajewski, A. Skeparovski, E. Guziewicz, N. Novkovski
Abstract
Al2O3/HfO2 multilayer stacks deposited by atomic layer deposition
(ALD) have been investigated from the view point of their application
in emerging charge-trapping non-volatile flash memories. Dielectric and
electrical properties, charge trapping, retention and endurance characteristics have been shown to depend strongly on the thickness of Al2O3 and
HfO2 sublayers as well as on the post-deposition annealing (PDA) steps.
O2 and N2 PDA introduce different kinds of electrically active defects in
Al2O3/HfO2 stacks. The results give convincing evidence that PDA in
O2 enhances substantially electron trapping in deep traps, hence charge
storage ability of stacks. RTA in N2 results in negligible memory windows
for thinner samples, i.e. it is not efficient in improving the charge storage
ability. Multilayered HfO2/Al2O3 stacks have a potential for implementation as charge trapping layer in non-volatile memory devices and their
charge storage ability could be tailored and enhanced by optimization of
stack parameters as well as annealing processes.
(ALD) have been investigated from the view point of their application
in emerging charge-trapping non-volatile flash memories. Dielectric and
electrical properties, charge trapping, retention and endurance characteristics have been shown to depend strongly on the thickness of Al2O3 and
HfO2 sublayers as well as on the post-deposition annealing (PDA) steps.
O2 and N2 PDA introduce different kinds of electrically active defects in
Al2O3/HfO2 stacks. The results give convincing evidence that PDA in
O2 enhances substantially electron trapping in deep traps, hence charge
storage ability of stacks. RTA in N2 results in negligible memory windows
for thinner samples, i.e. it is not efficient in improving the charge storage
ability. Multilayered HfO2/Al2O3 stacks have a potential for implementation as charge trapping layer in non-volatile memory devices and their
charge storage ability could be tailored and enhanced by optimization of
stack parameters as well as annealing processes.
Subjects