High-Density Read-Only Memory Disc withAg11In12Sb51Te26 Super-Resolution Mask Layer

Abstract

A novel read-only memory (ROM) disc with anAg11In12Sb51Te26 super-resolution masklayer is proposed and investigated for the first time to our knowledge.The carrier-to-noise ratio of more than 40 dB could be obtained fromsmall pits (380 nm), which are below the readout resolution limit(400 nm), in our dynamic setup with a wavelength of 632.8 nm andnumerical aperture of 0.40. Dependences of carrier-to-noise ratio onreadout power, readout velocity and film thickness are studied. Theresults show that the optimum film thickness is 20–50 nm and thecorresponding carrier-to-noise ratio is more than 40 dB at readoutpower of 4 mW and readout velocity of 2 m/s in our experiment. Thesuper-resolution readout mechanism for this ROM disc is also discussed.