Spin Transfer Torque Magnetic RAM (STT-MRAM) promises low power, great miniaturization prospective (e.g. 22nm) and easy integration with CMOS process. It becomes actually a strong non-volatile memory candidate for both embedded and standalone applications. However STT-MRAM suffers from important failure and reliability issues compared with the conventional solutions based on magnetic field switching. For example, a read current could write erroneously the stored data, the variability of ultra-thin oxide barrier drives high resistance variation and the injected current in the nanopillar induces lower lifetime etc.