Exploring variability and reliability of multi-level STT-MRAM cells

In this paper we have presented a comprehensive analysis of multi-valued STT-MRAM and their benefits and drawbacks. Results shows that in order to reduce read failures in scaled geometries, self-reference reading scheme is necessary. We have also shown that by choosing appropriate RA₁ and RA₂ (we define the feasible RA₁-RA₂ region in the design space), one can reduce both read and write failures. However, in order to achieve higher reliability, a thicker T ox is needed, which can further constrain the RA₁-RA₂ design space of multi-valued STT-MRAMs.