Disturb robust switching astroid curve of C-shaped cell with weakly coupled synthetic anti-ferromagnetic layer

In this paper, we propose a C-shaped cell with weakly coupled SAF (WSAF) layer, which features large H_c, small operational switching field and improved robustness against the writing disturbance with large field on hard axis. we have studied astroid curve of C-shaped cell using WSAF free layers, which improve half-selected problem with large field on hard axis. This technology is estimated to be extendable to 256-512Mb MRAM having chip area comparable with DRAM.