Application and Improvement of Precise Resistance Tracing Technique for a Toggle Mode MRAM Evaluation

• Published in: IEEE transactions on semiconductor manufacturing Vol. 21; no. 4; pp. 542 - 548
• Main Authors: Katoh, Y., Hada, H., Kasai, N.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01.11.2008; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Circuits; Electronics; Exact sciences and technology; Failure analysis; Giant magnetoresistance; High speed; Integrated circuits; Integrated circuits by function (including memories and processors); Magnetic analysis; Magnetic and optical mass memories; Magnetic field measurement; magnetic memories; Magnetic separation; Magnetic tunneling; Magnetization; magnetization reversal; Magnetoelectric, magnetostrictive, magnetoacoustic, magnetooptic and magnetothermal devices. Spintronics; Magnetoresistance; Magnetoresistive random access memory; measurement; Quadrants; Robustness; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Semiconductors; Storage and reproduction of information; Switches; Testing, measurement, noise and reliability; Tunneling; Magnetoresistive device; Magnetization reversal; Random access memory; Giant magnetoresistance; measurement; Magnetic storage; Magnetic tunneling junction; Non volatile memory; Failure analysis; Integrated circuit; Testing equipment; Robustness; magnetic memories
• ISSN: 0894-6507; 1558-2345
• DOI: 10.1109/TSM.2008.2004337

A precise evaluation technique was created for developing magnetoresistive 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 incomplete operation and failed cells, and revealed that the MTJ characteristics in the third quadrant are significantly related to disturb robustness in megabit MRAM. To improve sensitivity to failed cells, we prepared 16-kbit MRAM test structures with a high-speed failed-cell check mode. We found our technique to be a powerful method of failure analysis and expect it to accelerate MRAM development.