Effect of Adjacent Layers on Crystallization and Magnetoresistance in CoFeB/MgO/CoFeB Magnetic Tunnel Junction

Abstract

Crystallization must occur in order to obtain lattice matching between CoFeB and MgO in amorphous CoFeB/MgO/amorphous CoFeB magnetic tunnel junction (MTJ). However, the interface layer effect on the crystallization behavior is not yet clear. An aim of our experiments was to investigate the effects of various layers including Ta, MgO, Ru, and NiFe on the crystallization and transport properties in CoFeB/MgO/CoFeB MTJs deposited on SiO <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$_2$</tex> /Si and glass. It was found that the onset of crystallization of CoFeB and its specific orientation were dependent on the layer adjacent to CoFeB. The effects of crystallization on transport properties are also discussed.