Effects of annealing conditions on structural and ferroelectric properties of CeO2-HfO2 solid solution thin films on InAs substrates fabricated by chemical solution deposition

Abstract

CeO2-HfO2 solid solution thin films are fabricated on (100) InAs substrates by chemical solution deposition (CSD) method. The effects of annealing conditions (annealing temperature and atmosphere) on the structural and ferroelectric properties of CeO2-HfO2 solid solution thin films are studied. The results verified that ferroelectric phase of CeO2-HfO2 solid solution thin film could be induced on InAs substrate. In the temperature range studied (550 – 700 ºC), higher annealing temperature profits suppressing nonferroelectric monoclinic phase and promoting ferroelectric orthorhombic phase, and therefore improves ferroelectric polarization. For film annealed at 700 ºC, annealing in N2 leads to an enhanced ferroelectric polarization (2Pr of 33.9 μC/cm2) compared with annealing in O2. Importantly, all films can survive 1 × 108 cycles at an applied voltage of 20 V, and do not show significant retention losses, which are benificial for further application. This work highlights the feasibility of integrating CeO2-HfO2 ferroelectric thin films on III-V platform technology.