No‐Heating Deposition of Ferroelectric x%YO1.5–(100−x%)(Hf1−yZry)O2 Films

The no‐heating deposition of x%YO1.5–(100−x%)(Hf1−yZry)O2 (x = 0−0.09, y = 0, 0.25, 0.50, and 1) is achieved using a radio‐frequency magnetron sputtering method. To investigate the crystal structure and ferroelectric properties, epitaxial films are grown on (111)‐oriented indium tin oxide (ITO)/(111) Y‐stabilized zirconia (YSZ) substrates. The ferroelectric orthorhombic phase is obtained for the 5–7%YO1.5–95–93%HfO2 and 5%YO1.5–95% (Hf0.75Zr0.25)O2 films. The field‐induced phase transition from tetragonal to orthorhombic is confirmed for the 8%YO1.5–92%HfO2 and 5%YO1.5–95%(Hf0.50Zr0.50)O2 films. The remnant polarization (Pr) and coercive field (Ec) are 12–19 μC cm−2 and 2,000–2,500 kV cm−1, respectively. The piezoelectric response of 1 μm thick films is investigated for 6%YO1.5–94% HfO2, 7%YO1.5–93%HfO2, and 5%YO1.5–95%(Hf0.50Zr0.50)O2 films, which have piezoelectric coefficients (d33) of 1.0, 3.3, and 5.0 pm V−1, respectively. These results show no‐heating deposition of x%YO1.5–(100−x%)(Hf1−yZry)O2 films with ferroelectric and piezoelectric properties. No‐heating deposition of ferroelectric and piezoelectric films is essential for the fabrication of high‐performance devices to prevent thermal destruction and atomic diffusion of substrate materials. The no‐heating deposition of x%YO1.5–(100−x%)(HfyZr1–y)O2 films is investigated using a sputtering method. These films exhibit similar ferroelectric and piezoelectric behaviors to reported annealed films.