Investigation Into The Viability Of A Magnetic Thin Film As An Analog, Nonvolatile Memory Device

Abstract

A %50Co-50%Fe magnetic film of 1000Å has been used as the memory element fabricated on a silicon substrate to be used as a nonvolatile memory with read/write capabilities. A Hall element has been employed to detect the memory state of the device. The devices suffer from extreme leakage currents and breakdowns due to an erroneously prepared mask used during photolithography. This limits any measurements of the memory states to yield information only on the static behavior of the magnetic film. At the time of this writing, conclusive evidence is not available to argue for the viability of the device as an analog memory. However, along the way, some important findings have been reached: 1. The Hall element worked and contributes a negligible voltage drop during measurements of magnetic induction. 2. The Fe-Co alloy used showed a mechanical resilience through standard silicon processing. 3. During the annealing process in H₂/N₂ forming gas, films of 1000Å were observed to have rather smooth, homogeneous surfaces when viewed at 1000 X after 5 hours at 500°C. After 10 hours at the same temperature, the films appeared to be rather rough and heterogeneous. This evidence supports other experimental evidence indicating the difference in material and magnetic properties when comparing, thin films to bulk material. Further, the evidence indicates the need for further research on characterizing the annealing of thin films and exploring other properties unique to thin-film materials.