Periodic Reporting for period 1 - MAGALIGN (Magnetic alignment for high precision 3D assembly)
Okres sprawozdawczy: 2021-01-01 do 2022-06-30
The project takes advantage of the fact that ferromagnetic cobalt is used in vias and interconnects. Cobalt vias can be straightforwardly realized at the surface of a first wafer and used as magnetic alignment marks. As demonstrated in the ERC MAGICAL project, MRAM cells can be used as magnetic field sensors thanks to the spin transfer torque effect (STT). As a result, developments within the MAGALIGN project demonstrated an alternative magnetic field sensing method based on typical MRAM memory cells. Within the timeframe of the project, it was demonstrated that this new sensor technology can combine large range magnetic field measurements typical of Hall effect sensors, with high resolution of magneto-resistance sensors, while reducing the total sensor lateral width to only 50nm, while other sensors have typically 200-1000x larger dimensions. A partnership between Spintec (Grenoble, FR), Unistra (Strasbourg, FR) and FHNW (Muttenz, CH) is now established to develop the electronic circuitry and strategies towards further increase in resolution, sensitivity and range, combined with low power. The ultimate goal of high-resolution alignment still requires further improvements in sensor sensitivity. However as a sensor, the demonstrated STT junctions could already find applications in other fields. These domains range from industrial applications to the medical field, embedded either in a single small chip, or as an array of sensing units. Among application examples are industrial applications such as current sensing, fault detection, system alignment such as photolithographic masks, or medical applications with near-field sensing, magnetic tracking systems, or magnetic camera with extremely high density, unreachable with present technology of large MR or Hall sensitive elements.