On‐chip Diamond MEMS Magnetic Sensing through Multifunctionalized Magnetostrictive Thin Film
Zilong Zhang, Wen Zhao, Guo Chen, Masaya Toda, Satoshi Koizumi, Yasuo Koide, Meiyong Liao
Abstract
Abstract Electrically integrable, high‐sensitivity, and high‐reliability magnetic sensors are not yet realized at high temperatures (500 °C). In this study, an integrated on‐chip single‐crystal diamond (SCD) micro‐electromechanical system (MEMS) magnetic transducer is demonstrated by coupling SCD with a large magnetostrictive FeGa film. The FeGa film is multifunctionalized to actuate the resonator, self‐sense the external magnetic field, and electrically readout the resonance signal. The on‐chip SCD MEMS transducer shows a high sensitivity of 3.2 Hz mT −1 from room temperature to 500 °C and a low noise level of 9.45 nT Hz −1/2 up to 300 °C. The minimum fluctuation of the resonance frequency is 1.9 × 10 −6 at room temperature and 2.3 × 10 −6 at 300 °C. An SCD MEMS resonator array with parallel electric readout is subsequently achieved, thus providing a basis for the development of magnetic image sensors. The present study facilitates the development of highly integrated on‐chip MEMS resonator transducers with high performance and high thermal stability.