High-Speed Fabrication of Super-Resolution Near-Field Structure Read-Only Memory Master Disc using PtO_x Thermal Decomposition Lithography

摘要

We propose a new lithography technique using thermal decomposition of platinum oxide (PtO_x) for high-throughput master disc fabrication. The smallest pit size was evaluated to be 50 nm using a laser wavelength of 405 nm and a numerical aperture (NA) of 0.65; hence, it is one-twelfth the optical spot size. In addition, fabrication of pits with different shapes was examined, and its effects on super-resolution near-field structure (super-RENS) disc properties were studied. The readout signal characteristic evaluated on the basis of carrier-to-noise ratio (CNR) with an elliptical pit was 7 dB larger than that of the round one. The results demonstrated that this high-throughput fabrication technique is also useful for controling the pit shape for CNR improvement of super-resolution readout.