Toshihiro Usa

Design of Ni Mold for Discrete Track Media

Nano imprint lithography (NIL) and NIL mold formation play a vital role in discrete track media (DTM) production. In this paper, we created a nickel (Ni) mold for DTM production using an R-theta electron beam mastering device to draw data groove and servo information on a silicon substrate master, and transferred the resulting pattern to a nickel mold via an electroplating process. The resulting Ni mold exhibits a 90-nm track pitch (282 kTPI equivalent), 30-nm line width, 60-nm groove width, 60-nm land height, and 7-nm line width roughness (LWR). Since variations in downtrack LWR and line edge roughness (LER) on the Ni mold are much smaller than variations in the size of HDD media magnetic clusters, we believe the Ni mold production method that is the subject of this study can be successfully applied to the production of DTM molds for next-generation HDD media.

Fabrication of 20-nm half-pitch quartz template by nano-imprinting

We have been developing nanoimprint templates for the next-generation sub-20nm nanofabrication technology, with particular emphasis on duplicate fabrication of quartz templates created from Si masters. In general, the narrowing of pattern line widths is accompanied by concerns about whether resist will sufficiently fill such lines. Our development has concentrated on the filling property of resist in narrow lines and on pattern shape after release from the mold. Our findings indicated that pattern formability differs according to the type of resist monomer. We inferred that these differences are manifested in such behaviors as resist shrinkage after or during release of the mold. Using a novel resist that has good formability, we pursued quartz template duplication that employs UV-NIL. As a result, we demonstrated HP20nm quartz pattern formation using the duplication process. We were also verified NIL resist pattern resolution of HP17.5nm.