Tunable Sensing Performance of Linear Perpendicular TMR Sensor

Magnetic tunnel junctions (MTJ) are engineered with the film stack of crossed magnetization pattern structure for perpendicular tunnel magneto-resistance (TMR) sensor application. The fabricated devices show good linearity and stability. The temperature dependence and the noise level of the sensor are also characterized. We demonstrate that the sensitivity and linear range of the perpendicular pinned TMR sensors can be tuned in quite a large range by controlling the free layer thickness. This research provides guidance for the design and process optimization of the perpendicular sensors.