Fabrication and testing of deep submicron annular vertical magnetoresistive random access memory elements

Abstract

Ultrahigh density vertical magnetoresistive random access memory (invited)Long term stability of dry etched magnetoresistive random access memory elements High density submicron magnetoresistive random access memory (invited)

Bit Storage by 360$^{\circ}$ Domain Walls in Ferromagnetic Nanorings

“…Recently, a growing interest was attracted by a new MRAM cell design concept in which the storage element is made in the shape of a submicron-sized ring 5,6,7,8,9,10,11,12,13,14,15,16 . As was proposed in Ref.…”

“…Note that in the latter case the current densities required to affect the magnetization state are found to be quite high (exceeding 10 18,20 . Another proposal 7,13 has been to pass a current of variable polarity vertically through the sandwich structure, so that the resulting circular magnetic field favors a particular vortex orientation 27 . Here, we propose a new principle for the design of a robust MRAM cell based on thin film ferromagnetic nanorings (see Fig.…”

Size dependence of magnetization reversal of ring shaped magnetic tunnel junction

“…Most of researches in ring shape devices revealing uniform and specific switching process were only focused on magnetic single layer [3,4]. Recently, the concept was realized in current perpendicular to the plane giant magnetoresistance (CPP-GMR) systems [5] and for the first time in CPP-MTJ system in our previous work [6]. In this study, the size dependence of magnetization reversal of MTJ rings was investigated.…”

Polarization dependent switching of asymmetric nanorings with a circular field

“…The vortex state can have either clockwise (CW) or counterclockwise (CCW) circulation, which have degenerate energies in uniform applied fields. Nanorings have been proposed as data storage elements, [1][2][3][4][5][6][7][8][9] taking advantage of the stable equilibrium CW and CCW configurations with no stray field. Understanding and controlling the switching of nanorings is of fundamental interest and critical to progress towards data storage applications.…”