SBIR Phase I: Nanometer-Scale Magnetic-Tunnel-Junction Sensors

This Small Business Innovation Research (SBIR) Phase I project aims to demonstrate the feasibility of fabricating nanometer-scale magnetic-tunnel-junction (MTJ) sensors that are highly sensitive, operate at room temperature, and surpass the performance of existing magnetic sensors. Nanoscale MTJ sensors, currently unavailable in the marketplace, are urgently needed for sensing weak magnetic fields with nanometer-scale resolution. One application is a scanning magnetic microscope that can non-invasively measure the electrical current distribution of semiconductor chips down to the smallest spatial feature. Other applications include magnetic imaging arrays, biomagnetic sensors, and read/write heads for data storage devices. The project is to develop a process for fabricating sensors with unprecedented miniaturization. The feasibility study will address three key issues: 1) the large increase in junction resistance that accompanies the reduction of junction area will be minimized; 2) the nonlinear response caused by discrete domain-wall motions in small sensor elements will be overcome; and 3) the thermal fluctuations that become problematic as the anisotropy energy of the sensor is reduced will be stabilized. If successful, this will deliver versatile magnetic sensors with the potential to broadly impact the semiconductor, data storage, and biotechnology markets.