| 초록 |
The purpose of this research is to develop new etching process for achieving the vertical etch profile of magnetic tunnel junction stacks (MTJs) without degradation of ferromagnetic layers. During the conventional etch process, the ions and/or radicals decomposed from etch gases attack the surface of magnetic layer, resulting in a loss of magnetic property. To avoid this plasma damage, the particular gases containing C, H, and O elements such as CH3OH, C2H5OH, and CH4/O2 gases can be introduced to etch the magnetic layers. An inductively coupled plasma reactive ion etching equipment was employed to etch the CoPt superlattice in pure Ar, CH3OH/Ar, and CH4/O2/Ar gas mixtures. The CoPt superlattice multi-stack was used to measure the degradation of ferromagnetic layer with a vibrating sample magnetometer. In addition, the etch profiles were observed by using field emission scanning electron microscope and field emission transmission electron microscope. |
