Q. Stainer, L. Lombard, K. Mackay, R. C. Sousa, I. L. Prejbeanu, B. Dieny
This paper describes an original concept of thermally assisted MRAM in which memory and logic functions are combined in the same stack. The memory cell is represented by a magnetic tunnel junction having an exchange biased storage layer and a soft reference layer (called sense layer), replacing the conventional pinned reference layer. The write of the storage layer is ensured by a combination of heating pulses and magnetic stray fields created by the soft reference layer. The read is performed in a self-referenced manner by measuring the resistance variation associated to a field variation. This makes these memories much more tolerant to cell to cell variability. In addition, this stack intrinsically performs both a storage function and a comparison (XOR) function. This device called a Magnetic Logic Unit (MLU™) is particularly suited for security applications and Content Addressable Memories.
