A wireless, battery-free temperature sensor utilizing the morphotropic phase boundary of HfxZr1−xO2 thin film

Abstract

The development of efficient and self-sustaining wireless sensors plays a crucial role in various applications. Temperature is an essential parameter within wireless sensor networks. It is vital for process regulation, ensuring product quality, and preventing equipment malfunctions. Conventional temperature sensors are often insufficient because they require physical contact or rely on batteries for signal transmission. Furthermore, current solutions frequently conflict with traditional mass production and miniaturization techniques. This paper introduces a wireless temperature sensor that is compatible with conventional semiconductor technologies and operates without batteries. The sensor accurately measures temperature changes by detecting variations in the dielectric constant of the hafnium zirconium oxide (HZO) morphotropic phase boundary (MPB). Wireless signal transmission utilizes passive inductor-capacitor resonance circuits. The MPB HZO temperature sensor demonstrates a temperature sensitivity of 0.15 °C K⁻¹ over a wide temperature range from 293 K to 373 K. Additionally, it shows a sensitivity of 0.01 MHz K⁻¹ within the frequency range of 29.71 MHz to 30.50 MHz. This sensor achieves a maximum wireless detection distance of 10 mm. Combining wireless and battery-free sensor technology with MPB HZO thin films offers a practical alternative for precise and affordable temperature monitoring. This technology has potential applications across diverse fields.