MAGNETIC RANDOM ACCESS MEMORY DEVICES INCLUDING MULTI-BIT CELLS

摘要

A magnetic random access memory ("MRAM") cell includes: (1) a first magnetic layer having a first magnetization direction and a magnetic anisotropy axis; (2) a second magnetic layer having a second magnetization direction; and (3) a spacer layer disposed between the first magnetic layer and the second magnetic layer. The MRAM cell also includes a field line magnetically coupled to the MRAM cell and configured to induce a write magnetic field along a magnetic field axis, and the magnetic anisotropy axis is tilted relative to the magnetic field axis. During a write operation, the first magnetization direction is switchable between m directions to store data corresponding to one of m logic states, with m>2, at least one of the m directions is aligned relative to the magnetic anisotropy axis, and at least another one of the m directions is aligned relative to the magnetic field axis.