High annealing temperature assisted broadening of the ferroelectric concentration window in Al:HfO2 MFS structures

Abstract

The effects of annealing temperature (T a) on the crystal structure and ferroelectric properties of Al:HfO2 films with various ALD cycle ratios were examined. A ferroelectric T a range was obtained with respect to the cycle ratio and a linear relationship was observed between the best T a and the particular cycle ratio. Further increasing the cycle ratio from the conventional 4.1 mol% to the current 7.9 mol% slightly decreased 2P r from 23.6 μC cm-2 to 20.9 μC cm-2, implying a significant widening of the ferroelectric concentration range for the Al:HfO2 nanofilm due to the high annealing temperature.