Abstract
We report the resin material dependence of the shape of pits obtained by thermal direct mastering (TDM), which is a heat-mode mastering method utilizing the thermal decomposition of resins. By applying suitable resins, both circular and crescent pits can be obtained by TDM. This difference in shape was considered to originate from the temperature difference between the glass transition temperature and the thermal decomposition temperature of the resins. The resin with a relatively small temperature difference was suitable for the fabrication of the circular pits and random patterns, and the resin with a large temperature difference was suitable for the fabrication of the crescent pits and monotone patterns with high linear density. By using a deep ultraviolet (DUV) laser mastering system with a wavelength of 257 nm and a numerical aperture of 0.90, a monotone pattern of 40-nm-length pits was fabricated by applying a novolak-type resin with a relatively large temperature difference.