A nano-scale polish process with improved desired characteristics of low roughness and
low scratch counts has been developed using a novel polish tape and diamond abrasive on hard glass
substrates. For an improved polishing performance with high removal rate properties and preventing
scratches, a novel tape was developed having a nano-fiber level, densified surface and a flatter surface
by slenderizing the fiber and dispersing ultrafine fiber using an innovative technique. Using this novel
polishing tape with a fiber size of 200nm, one can produce a 17% lower surface roughness (Ra) (from
1.05A to 0.87A) and a reduced polished surface scratch count of 53 reduced to 18. The novel
nano-cluster diamond abrasive is synthesized from carbon atoms of explosives created by detonation
in a closed chamber under an oxygen leaked atmosphere ambient. Several crystals are bonded
together by layers of non-diamond carbon and other elements, forming aggregates with a nano-cluster
structure. Using this novel nano-cluster diamond along with an ultra-fine diamond mixture with a
nominal size of 15nm, one is able to produce an improvement of a 48% lower surface roughness Ra
(from 0.87A to 0.45A) and a lower polishing surface scratch count reduced from 18 to 7. Overall,
these results indicate that a smoother and a reduced scratch polished substrate results in a significant
improvement in disk defects and related magnetic performances.
