Instant-on Nonvolatile Nanoelectronics
Kang L. Wang, Raytheon Professor of Physical Science and Electronics, University of California
An exposé of instant-on nonvolatile systems using collective
spins or nanomagnets will be discussed for achieving low energy dissipation
approaching the Maxwell-Shannon-Landaur limit.
In meeting the energy dissipation challenge of scaled CMOS, spintronics using collective effects such as nanomagnetics offers the advantage of minimizing off state power dissipation due to its nonvolatile state. I will describe the progress in energy-efficient MgO-based magnetic tunnel junction (MTJ) bits for high-speed spin-transfer-torque magnetoresistive random access memory (STT-MRAM)[i] in FENA and WIN, and related DARPA projects. STT-MRAM devices can be integrated directly on top of front-end processed CMOS using back-end process as in the case of metal interconnects. Issues for design of nonvolatile circuit gates will be discussed for a possible implementation of FPGA. Challenges to meet the needs of nonvolatile electronics using STT as well as those beyond will also be discussed.
Next, I will discuss the recent work on the principles and the use of voltage controlled magnetism to further reduce the power dissipation. This will minimize the switching energy beyond those of STT-RAM. New nonvolatile, Instant-on integrated circuits chips and systems may emerge using these technologies.
 P.K. Amiri, Z.M. Zeng, P. Upadhyaya, G. Rowlands, H. Zhao, I.N. Krivorotov, J.-P. Wang, H.W. Jiang, J.A. Katine, J. Langer, K. Galatsis, K.L. Wang, "Low Write-Energy Magnetic Tunnel Junctions for High-Speed Spin-Transfer-Torque MRAM", IEEE Electron Device Letters, Vol. 32, No. 1, pp. 57-59, January 2011.