Optimized Soft Magnetic Electrodes for Ultra-sensitive Magnetic Tunnel Juction Field Sensors

This SBIR project aims to develop a new class of low-field magnetic sensors based on magnetic tunnel junctions with magnesium oxide (MgO) tunnel barriers. The Phase II effort will continue the optimization of sensor performance, based on three major research thrusts. First of all, we will continue the magnetic engineering effort, turning the properties of the two key magnetic electrodes, in order to ensure that the sensor response is linear and reproducible. Secondly, we will systematically attack the two dominant sources of electrical noise in our MTJ devices. By making careful choices of sensor shape, mask layout, and annealing and processing parameters, we will minimize the 1/f and shot noise in our devices. Finally, we conduct research into possible ¿field modulation¿ techniques for integration into our sensor design. The goal of such techniques will be to artificially modulate the DC magnetic field which is seen by the sensor, to avoid excessive sensor noise typically seen at low frequencies.