Structure evolution and charge hysteresis in buried Hafnia-Alumina oxides

Abstract

Analysis of the high-k buried oxide phase evolution by the X-ray study, pseudo-MOSFET and CV measurements was used to separate the ferroelectric and interface dipole polarization, and charge trapping up to 300 °C. The thermal budgets during the rapid thermal annealing (RTA) 30 s at temperatures 600 to 1000 °C were established for different hafnia based stacks to ensure the recrystallization of HfO2 layers and preservation of ferroelectric hysteresis. The highest hysteresis was obtained at the RTA stepwise temperature increase to 900 °C for the stack with supercicles HfO2:Al2O3 (10:1).