The ferroelectric and piezoelectric properties of (Hf_1-x Ce _x )O₂ films on indium tin oxide/Pt/TiO _x /SiO₂/(100)Si substrates obtained using a no-heating radio-frequency magnetron sputtering deposition method

Abstract The effect of composition and film thickness on the ferroelectric and piezoelectric properties of (Hf1-x Ce x )O2 films deposited without substrate heating was investigated. (Hf1-x Ce x )O2 films with various x values (x=0.07–0.27) and thickness (150–880 nm) were deposited via radio-frequency (RF) magnetron sputtering on indium tin oxide (ITO)/Pt/TiO x /SiO2/(100)Si substrates. The crystalline phases of the films were observed by X-ray diffraction. The measurements of electrical properties revealed ferroelectric phases in the x range of 0.11–0.21. The film with x=0.16 exhibited the maximum remanent polarization (P r) of 15 µC/cm2, as well as the highest effective piezoelectric coefficient. In addition, the ferroelectric and structural properties remained almost unchanged with increasing film thickness. Therefore, the no-heating deposition of ferroelectric (Hf1-x Ce x )O2 films and their phase stability with respect to thickness were demonstrated for the first time. This work provides a pathway for the deposition of ferroelectric (Hf1-x Ce x )O2 films on flexible, wearable sensors.