STT-MRAM: A Robust Embedded Non-Volatile Memory with Superior Reliability and Immunity to External Magnetic Field and RF Sources

• Published in: 2021 Symposium on VLSI Technology pp. 1 - 2
• Main Authors: Naik, V. B., Yamane, K., Kwon, J., K, S., Lim, J. H., Ali, Z., Behin-Aein, B., Chung, N. L., Hau, L. Y., Chao, R., Chiang, C., Huang, Y., Pu, L., Otani, Y., Dixit, H., Jang, S. H., Balasankaran, N., Tan, F., Neo, W. P., Goh, L. C., Toh, E. H., Ling, T., Ting, J. W., Yoon, H., Congedo, G., Mueller, J., Pfefferling, B., Kallensee, O., Vogel, A., Merbeth, T., Seet, C. S., Wong, J., Bordelon, J., You, Y. S., Soss, S., Chan, T. H., Quek, E., Siah, S. Y.
• Format: Conference Proceeding
• Language: English
• Published: Japan Society of Applied Physics (JSAP) 13-06-2021
• Subjects: Electromagnetic interference; Magnetic fields; Nonvolatile memory; Process design; Radio frequency; Robustness; Very large scale integration
• ISSN: 2158-9682

We report STT-MRAM's robustness, superior reliability and immunity performance to external magnetic field and RF sources for next-generation embedded-MRAM (eMRAM) technology based on 22FDX ® +RF+MRAM. Using 40Mb eMRAM integrated in 22FDX ® , we demonstrate Write/Read repeatability performance with BER variation of <0.2 PPM with ECC-OFF and zero failure with ECC-ON at -40~125°C. We show angle dependence of standby magnetic immunity and ways to improve it with optimized shielding designs. Using a specially designed RF-MRAM EMI chip, we demonstrate no impact of RF interference on MRAM and vice versa. Furthermore, using optimized MTJ process, design and testing schemes, we show <2 PPM post 5x solder reflow performance and zero mean endurance failure after 100K cycles at -40°C.