Engineering the Switching Behavior of Nanomagnets for Logic Computation Using 3-D Modeling and Simulation.

In this paper, we show the feasibility of tuning both the location of domain wall nucleation and the required nucleation field by changing the geometry of nanomagnets using shadowing effects. The perpendicular anisotropy is locally reduced by shadowing effects during sputter deposition. A 3-D model based on experimental measurements of fabricated nanomagnets has been developed. Experimental data from atomic force microscopy measurements and anisotropy measurements of fabricated Co/Pt-nanomagnets allow to realistically model the anisotropy and geometry of the nanomagnets. Micromagnetic simulations based on the developed 3-D model have been performed. It is shown that increasing the undercut in the resist decreases the switching field of the nanomagnets. By varying the tip geometry of the nanomagnet, the switching field can be further decreased, and subsequently, the nucleation point can be controlled, making this technique feasible for the use in perpendicular nanomagnetic logic circuitry. [ABSTRACT FROM AUTHOR]