Magnetic Content Addressable Memory

In this paper, we propose a magnetic tunneling junction (MTJ)-based content addressable memory (CAM) design to simplify CAM bit from ten MOSFETs to one MTJ device. The MTJ CAM cell consists of a thin top electrode and vertical ring-shaped bottom electrode. The spin orientations in top and bottom electrodes can be programmed individually. The tunneling junction resistance represents the matching status between the data stored in top and bottom magnets. The top magnet is intentionally made thin so that it can be programmed with a low magnetic field without disturbing the thick bottom magnet. The bottom vertical ring-shaped magnet has programming-current enclosed inside the ring. The programming magnetic field is confined within the ring-shaped magnet. Our simulation based on Ansoft Maxwell (Pittsburgh, PA) software shows magnetic field confinement provides an order of magnitude difference between magnetic fields in the top and the bottom magnets separated by 2 nm. Landau-Liftshitz-Gilbert (LLG) micromagnetic simulations confirm that either magnet can be programmed without disturbing the other one