In this work, we present significant charge trapping memory effects of the metal-hafnium oxide-SiO2-Si (MHOS) structure. The devices based on 800°C annealed HfO2film exhibit a large memory window of ∼5.1V under ±10V sweeping voltages and excellent charge retention properties with only small charge loss of ∼2.6% after more than 104s retention. The outstanding memory characteristics are attributed to the high density of deep defect states in HfO2films. We investigated the defect states in the HfO2films by photoluminescence and photoluminescence excitation measurements and found that the defect states distributed in deep energy levels ranging from 1.1eV to 2.9eV below the conduction band. Our work provides further insights for the charge trapping mechanisms of the HfO2based MHOS devices.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)