22nm STT-MRAM for Reflow and Automotive Uses with High Yield, Reliability, and Magnetic Immunity and with Performance and Shielding Options

• Published in: 2019 IEEE International Electron Devices Meeting (IEDM) pp. 2.7.1 - 2.7.4
• Main Authors: Gallagher, W.J., Lee, George, Shih, Yi-Chun, Lee, Chia-Fu, Lee, Po-Hao, Wang, Roger, Shen, Kuei- Hung, Wu, J. J., Wang, Wayne, Chuang, Harry, Chien, Eric, Chiang, Tien-Wei, Huang, Jian-Cheng, Shih, Meng-Chun, Wang, C.Y., Weng, Chih-Hui, Chen, Sean, Bair, Christine
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01-12-2019
• ISSN: 2156-017X
• DOI: 10.1109/IEDM19573.2019.8993469

We demonstrate high yield results from a solder-reflow-capable spin-transfer-torque MRAM embedded in 22nm ultra-low leakage (ULL) CMOS technology. The technology supports -40 to 150°C operation and data retention though six solder reflow cycles and far exceeding 10 years at 150°C. Ten year native magnetic field immunity is >1100 Oe at 25°C at the 1ppm bit upset level. A shield-in-package solution demonstrates <; 1ppm bit upset rates from a disc magnet providing 3.5 kOe disturb field exposure for ~80 hours at 25°C. Trading off reflow capability, using smaller CD magnetic tunnel junctions, higher performance is achieved, for example read signal development times of 6ns at 125°C and average write pulse times slightly over 30ns at -40°C in a 20Mb design.