As the magnetic storage industry roadmap calls for aggressive terabit/in2 densities over the next few years, the shift from
the current planar media to patterned media; grooved surfaces (discrete track media / DTM) and/or individually defined
magnetic dots (bit patterned media / BPM), will be necessary. Both types of patterned media require lithography to
produce the pattern on the disk and the most promising lithography candidate today is nano-imprint lithography (NIL).
During the imprinting process a thin, round, transparent template made of quartz is functioned as a mold to inversely
transfer the features from its surface to the patterning medium on the disks by direct contact. One issue with this
technique is the high probability of defects due to repeated contact of the template with the resist before, during, and
after UV radiation. Defect management through template cleaning, inspection and defect characterization is critical to
preserve integrity of the process.
In this paper, advanced acid-free cleaning combined with MegaSonic treatment for defect elimination is investigated for
effectiveness on discrete track recording (DTR) and BPM patterned templates. For the experiments, templates containing
250KTPI (100nm track pitch) full surface DTR pattern, 450 KTPI (56nm track pitch) with narrow band DTR pattern,
and 250Gdpsi (50nm track pitch) with narrow band BPM pattern are used. The effect of MegaSonic cleaning on the
pattern integrity of fragile features is studied. General characterization of defect attributes is made feasible through a
series of imprinting and template cleaning cycles focused on resist residues and contaminant removal. Imprinted disks
are analyzed using Candela disk inspection and SEM imaging of the pattern. Template cleaning is performed using
HamaTech MaskTrack TeraPure automated template cleaning system.