A. Mejdoubi, G. Prenat, and B. Dieny Magnetic Tunnel Junction (MTJ) devices are CMOS compatible with high stability, high reliability and non-volatility. A macro-model of MTJ with precessional switching is presented in this paper. This model is based on Spin-Transfer Torque (STT) writing approach. The current-induced magnetic switching and excitations was studied in structures comprising […]

Spinelectronics is a very rapidly expanding area of R&D which merges magnetism and electronics (Nobel Prize 2007). Since the discovery of giant magneto-resistance (GMR) in 1988, several breakthroughs have further boosted this field [spin-valves 1990, tunnel magneto-resistance (TMR) 1995, spin-transfer 1996, voltage controlled magnetic properties 2004]. The phenomenon of spin-transfer is particularly attractive both from […]

Charge- and spin-diffusion equations, taking into account spin-diffusion and spin-transfer torque, were numerically solved using a finite element method in complex noncollinear geometry. As an illustration, this approach was used to study the spin-dependent transport in a two-dimensional model giant magnetoresistance metallic pillar sandwiched between extended electrodes as is the case in magnetoresistive heads for […]

A recent report from ITRS ERD/ERM working group has identified STT MRAM and RedoxRAM as the most promising candidates for emerging scalable and manufacturable non-volatile memories1. This paper is focused on MRAM. It explains how the heating produced by Joule dissipation around the tunnel barrier of magnetic tunnel junctions (MTJ) can be used to assist […]

This paper is focused on thermally assisted magnetic random access memories (TA-MRAMs). It explains how the heating produced by Joule dissipation around the tunnel barrier of magnetic tunnel junctions (MTJs) can be used advantageously to assist writing in MRAMs. The main idea is to apply a heating pulse to the junction simultaneously with a magnetic […]

Q. Stainer, L. Lombard, K. Mackay, R. C. Sousa, I. L. Prejbeanu, B. Dieny This paper describes an original concept of thermally assisted MRAM in which memory and logic functions are combined in the same stack. The memory cell is represented by a magnetic tunnel junction having an exchange biased storage layer and a soft […]

R.C. Sousa, S. Bandiera, M. Marins de Castro, B. Lacoste, L. San-Erneterio-Alvarez, L. Nistor, S. Auffret, U. Ebels, C. Ducruet, I. L. Prejbeanu, L. Vila, B. Rodrnacq, B. Dieny This work reports on advances in MRAM cells aiming at sub-nanosecond switching and for sub-20nm technology nodes. Ultrafast precessional spin-transfer switching in elliptical magnetic tunnel junction […]

In WP1, studies were conducted to understand the mechanisms responsible for the dielectric breakdown in magnetic tunnel junctions (MTJs). A key asset of STT-MRAM is their write endurance which is much better than in all other technologies of non-volatile memories (FLASH, 105 cycles; PCRAM, 109 cycles; ReRAM, 1010 10 cycles). Combined with their speed (switching time 1-5ns), and density […]

Une jonction tunnel magnétique exploite des variations de résistance électrique sous l’effet d’un champ magnétique. Des chercheurs de l’Inac ont montré que l’insertion d’une couche « tampon » entre deux structures cristallines différentes peut augmenter de 75% la magnétorésistance d’une jonction à aimantation perpendiculaire, ce qui offre la perspective d’une réduction significative de la consommation […]

Perpendicular Anisotropy Materials for High-Density Non-volatile Magnetic Memory Cells Description The project aims at building the knowledge to fabricate perpendicular anisotropy magnetic tunnel junctions, and more generally the realization of perpendicular anisotropy layers for use as magnetic tunnel junction electrodes or perpendicular spin polarisers. The perpendicular anisotropy material development, will allow the demonstration of four […]