Effect of SiO2 Addition to PtOx Recording Layer of Super-Resolution Near-Field Structure Disc

A dielectric material (SiO 2 ) was added to the PtO x recording layer of a recently developed super-resolution near-field structure (super-RENS) disc to enhance the readout durability. The PtO x –SiO 2 (Pt 8.4 Si 21.1 O 70.5 ) composite layer was prepared by a chip-on-target sputtering method. The recorded mark became significantly solid-filled when the prepared layer was used to replace the PtO x layer of the original disc. The carrier-to-noise ratio obtained for the 100 nm marks (laser wavelength: 405 nm, numerical aperture: 0.65) was 44 dB. It was possible to readout 7.5 × 10 4 times until the initial carrier-to-noise ratio (CNR) decreases by 3 dB; this is a more than one-order-of-magnitude enhancement compared with at in the simple PtO x case. Readout laser power was not reduced. This enhancement is achieved as a result of improving the recording layer of the super-RENS disc.