Ion beam deposition and oxidation of spin-dependent tunnel junctions

This is the authors' abstract. We don't add key points for this paper.

Spin dependent tunnel junctions showing tunnel magnetoresistance (TMR) values of 39/spl sim/41% were fabricated using Ion Beam Deposition (IBD). Both the electrodes and the aluminum layer deposition were done by IBD. The aluminum oxidation was performed using the assist gun with an oxygen beam (+30 V acceleration voltage applied on the grids) using mixed O/sub 2//Ar plasma. The oxidation was monitored in real time with a residual gas analyzer (RGA). The junction area is defined by lithography, down to 3/spl times/2 /spl mu/m/sup 2/. As-deposited junctions with 15 /spl Aring/ of Al showed TMR of 27/spl sim/29%, independent of the junction area, with resistance-area products of 0.8/spl sim/1.6 M/spl Omega//spl times//spl mu/m/sup 2/. This TMR value reached 40% upon annealing at 290/spl deg/C, with resistance decreasing to 0.5/spl sim/0.8 M/spl Omega//spl times//spl mu/m/sup 2/.