Ferroelectric properties of gradient doped Y2O3:HfO2 thin films grown by pulsed laser deposition

Abstract

A HfO2-based thin film is a nanoscale ferroelectric material with a high-k dielectric and CMOS compatibility, which make it a promising candidate for high-performance electronics. Here, we demonstrate the synthesis of a ferroelectric Y-doped HfO2 (HYO) thin film by pulsed laser deposition. This HYO thin film is gradient doped by alternately depositing a HfO2 ceramic target and a Y2O3 ceramic target. In the films, the orthorhombic phase, ferroelectric phase, is proved by grazing incidence x-ray diffraction and scanning transmission electron microscopy measurements. Moreover, the HYO thin film embraces outstanding ferroelectric and dielectric properties, its remanent polarization is up to 10.5 μC/cm2, and the dielectric constant is 27. The 180° inversion of the domain can be observed in a piezoelectric power microscopy image, while the phase contrast of the write domain fades with time. Therefore, this work provides a reliable approach to obtain a ferroelectric HYO thin film, which enables great potential in future high-performance nanoelectronics.