A Precise Resistance Tracing Technique for a Toggle Mode MRAM Evaluation

A precise evaluation technique was created for developing magnetic random access memory (MRAM), especially memory that operates in a toggle-writing mode. This technique enables us to observe the detailed resistance transition of magnetic tunneling junction (MTJ) cells during complicated write operations. It was used to analyze failed cells and revealed that the MTJ characteristics in the third quadrant are significantly related to disturb robustness in megabit MRAM. We found our technique to be a powerful method of failure analysis and essential to accelerating MRAM development.