MULTILAYERED MAGNETIC THIN FILM STACK AND NONVOLATILE MEMORY DEVICE HAVING THE SAME

摘要

The present invention relates to a multilayer magnetic thin film stack having properties of reliable data recording and long-term data retention, and a nonvolatile memory device using magnetic tunnel junction (MTJ). The multilayer magnetic thin film stack according to an embodiment of the present invention includes the MTJ including: a tunneling wall layer; a magnetic pinned layer on a first surface of the tunneling wall layer; and a magnetic free layer on a second surface opposite to the first surface of the tunneling wall layer. In an embodiment, at least one from the magnetic pinned layer and the magnetic free layer includes: a CoFe-based first magnetic layer having a body centered cubic structure adjacent to the tunneling wall layer, and containing cobalt (Co) and iron (Fe); a second magnetic layer coupled to the CoFe-based first magnetic layer such that the second magnetic layer exchanges magnetism with the CoFe-based first magnetic layer; and a first spacer layer disposed between the CoFe-based first magnetic layer and the second magnetic layer, and including a stacked structure of a tantalum (Ta) layer adjacent to the CoFe-based first magnetic layer and a ruthenium (Ru) layer adjacent to the second magnetic layer.