Magnetic MRAM memory and magnetic field sensor: multi-functionality for 3D assembly In the last few years people are moving from planar technology towards 3D integration, this is due to the fact that the latter has lower production costs, higher versatility and the final device is more compact than for the standard planar technology. 3D integration consists into stacking wafers one on top to the other; to this end, a very problematic issue is the wafers misalignment. When wafers aren’t well aligned, we can have, in the worst case, diffusion of Cupper into the Silicon Dioxide; anyway, the lower is the surface area bonded and the lower is the current that can pass through the device, breaking down its efficiency.