Paper Title
Reliability Enhancement Hybrid Sensing Scheme for Spin-Transfer-Torque MRAM

A novel hybrid sensing scheme with enhanced reliability for Spin-Transfer-Torque MRAM (STT-MRAM) was proposed. The sensing scheme performs a mid-point reference read and a grey zone (GZ) cell detection process where a STT-MRAM cell is determined if it falls within the resistance overlapping zone. Based on the detection outcome, weak cells within the GZ that are highly susceptible to read error will undergo a second process variation tolerant non-destructive self-reference sensing (NSRS). Monte-Carlo simulation across process variation and read currents corners demonstrate the enhanced read reliability in the proposed sensing scheme with an average of 44.7%, 92.2% and 95.3% improvement of bit error rate (BER) over the conventional mid-point reference sensing technique with 5%, 8% and 10% standard deviation of the MTJ diameter, respectively. With an extended GZ detection range, the respective BER can be further reduced by 91.3%, 87.7% and 82.3%. Index Terms - Bit Error Rate, Hybrid Sensing, Monte-Carlo Process Variation, Resistance Overlapping, Stt-Mram, Self-Reference Sensing.