By Topic

A Three-Terminal Approach to Developing Spin-Torque Written Magnetic Random Access Memory Cells

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

9 Author(s)
Braganca, P.M. ; Hitachi Global Storage Technol., San Jose, CA ; Katine, J.A. ; Emley, N.C. ; Mauri, D.
more authors

Using a self-aligned fabrication process together with multiple-step aligned electron beam lithography, we have developed a nanopillar structure where a third contact can be made to any point within a thin-film multilayer stack. This substantially enhances the versatility of the device by providing the means to apply independent electrical biases to two separate parts of the structure. Here, we demonstrate a joint magnetic spin-valve (SV)/tunnel junction structure sharing a common free layer nanomagnet contacted by this third electrode. A spatially nonuniform spin-polarized current flowing into the free layer via the low-resistance SV path can reverse the magnetic orientation of the free layer as a consequence of the spin-torque (ST) effect, by nucleating a reversal domain at the spin injection site that propagates across the free layer. The free layer magnetic state can then be read out separately via the higher resistance magnetic tunnel junction (MTJ). This three-terminal structure provides a strategy for developing high-performance ST magnetic random access memory (ST-MRAM) cells, which avoids the need to apply a large voltage across a MTJ during the writing step, thereby enhancing device reliability, while retaining the benefits of a high-impedance MTJ for read-out.

Published in:

Nanotechnology, IEEE Transactions on  (Volume:8 ,  Issue: 2 )