Study of grain-patterned and highly ordered L1₀-FePt HAMR media using reactive molecular dynamics method

Embedded Mask Patterning (EMP) has been proposed as a cost-effective fabrication method to be capable of patterning sub-5-nm grain sizes for highly ordered L1₀-FePt media for Heat-Assisted Magnetic Recording (HAMR). Understanding the etching mechanism of FePt is critical to maintaining the highly ordered L1₀ structure and low damage to magnetic grains. In this research, a reactive Molecular Dynamics (MD) model is developed to study methanol (MeOH) plasma etching on highly ordered continuous L1₀-FePt media film. The model describes the reactive interaction mechanism between the plasma products CO/H₂ molecules and Fe/Pt atoms. It shows the dominant Fe-C interaction upon the dissociation of CO ligands leads to formation of large and volatile Fe_n-C clusters contributing to high chemical etch yield.