Read/Write Mechanism for a Scattered Type Super-Resolution Near-Field Structure Using an AgOx Mask Layer and the Smallest Mark Reproduced

A working mechanism for a scattered type super-resolution near-field structure (super-RENS) disk using a silver oxide (AgO x ) mask layer has been studied experimentally. The AgO x mask layer has five possible states depending on the laser power: AgO x (as-depo), uniformly dispersed Ag particles (after the initialization of 3.5 mW), Ag cluster (4–5 mW), Ag diffusion (5.5–7.5 mW), and a Ag ring structure (greater than 8 mW) for an objective lens numerical aperture of 0.5, a laser wavelength of 826 nm and a medium velocity of 2 m/s. On the other hand, the GeSbTe recording layer has the following possible states: crystal, halfway amorphous, completely amorphous, and gas bubble associated with Ag particles. For super-resolution read power (4 mW), the mask layer will have a Ag ring structure that increases both the signal carrier to noise ratio and the resolution limit. We improve the resolution limit of 413 nm to 50 nm at the duty ratio of 10% for the write optical pulse.