La-Doped HZO (La:HZO) Ferroelectric Devices Toward High-Temperature Application

This work reports lanthanum-doped hafnium zirconium oxide (La:HZO) ferroelectric (FE) devices with polarization behavior in high-temperature conditions spanning 25 °C–300 °C. Our findings reveal a significant transition to antiferroelectric (anti-FE)-like behavior as temperature rises, accompanied by a decline in remnant polarization (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${P} _{\text {r}}$ </tex-math></inline-formula>). In addition, the temperature-dependent endurance behavior in La:HZO FE devices shows that the anti-FE polarization behavior in the pristine state can be waken to pure FE hysteresis by field cycling below 150 °C. As the temperature further increases over 200 °C, earlier dielectric breakdown of the devices was observed, which may be attributed to the suppression of wake-up effect and increased leakage. These experimental insights provide crucial understanding and potential advance for the functionality of HZO-based FE devices in high-temperature environments.