Structures of Giant Magnetoresistance Sensors for Magnetic Bead Detection

This study explores the fabrication of giant magnetoresistance (GMR) sensors through the microelectromechanical systems (MEMS) process. Moreover, it investigates the magnetic properties of these sensors across various structural parameters. In particular, the study evaluates the effects of variations in four specific parameters of a GMR sensor on magnetic bead signals, aiming to achieve high sensitivity of the sensor and a high signal-to-noise ratio (SNR) output. Dual ac modulation is employed for magnetic bead signal detection. The results indicate that a sensor with a linewidth of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1~\mu $ </tex-math></inline-formula>m and line spacing of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$5\mu $ </tex-math></inline-formula>m exhibits the highest signal output and a higher SNR.