Fabrication of Planarized Discrete Track Media Using Gas Cluster Ion Beams

Fabrication of planarized discrete track media (DTM) by using gas cluster ion beams (GCIB) was demonstrated. Line-and-space patterns were fabricated using nanoimprint lithography and ion beam etching. These patterns were refilled by TiCr films, and the TiCr surface was planarized using Ar and N₂-GCIBs. The GCIB process yielded excellent planarization of these patterns owing to the preferential modification of surface bumps and enhancement of the surface motion of atoms by GCIB irradiation. The flyability test of a slider flying at a 10-nm height on the DTM planarized with GCIBs indicated an almost 10% reduction in the acoustic emission (AE) output. Further, magnetic force microscope (MFM) and Kerr rotation measurements revealed that GCIB planarization did not produce any significant change in the magnetic characteristics of DTM. It was demonstrated that GCIB planarization is effective for fabricating DTM or similar structures such as bit-patterned media (BPM).