Effect of capping layer on the crystallization of amorphous CoFeB

We investigated the effects of capping layer on the crystallization of amorphous top-CoFeB electrode in the glass/CoFeB/MgO(001)/CoFeB/cap stack. Evolution of texture and crystallization of the top-CoFeB electrode can be affected by the texture and the crystallinity of the capping layer. When the (002)-textured Ru capping layer was used, a (110) texture of CoFeB was developed during annealing at 350°C for 90 min. On the other hand, when the amorphous TiAl capping layer was used, a (002) texture of the CoFeB was developed during crystallization due to MgO (001) texture seeding effect. Consequently, the texture evolution of the amorphous top-CoFeB electrode during annealing could be controlled by the texture and crystallinity of the adjacent capping layer.