Faster and denser spin-tunneling random access memory (STram)

The spin tunneling junctions Co/Al/sub 2/O/sub 3//Ni/sub 80/Fe/sub 20/ provide an excellent means of storing a binary datum in the hard component (Co), and sensing its remanent state by switching the soft component (NiFe) in such a way that the magnetic state of the hard component remains unaltered. In this paper, it is clarified by a dynamic model that the switching is caused by the incoherent rotation of the magnetization in the fine thin film pattern and the read access time for a micro-structured spin tunneling with area of 0.256 /spl mu/m/spl times/0.256 /spl mu/m is 0.9 ns. In addition, a magnetic flux closure design was found to reduce the crosstalk by about a factor of five, compared with a conventional keeper-less design, which will be the most favored approach for achieving 10/sup 9/ bits/cm/sup 2/ areal density.