High-resolution blue-laser mastering using an inorganic photoresist

An inexpensive and practical mastering technology was developed using a blue-laser optical system with a wavelength;. of 405 nm and numerical aperture (NA) of 0.95 comprising an inorganic photoresist. The resist system showed a higher resolution for a successful 130 nm pit patterning than that obtained by an ordinary organic photoresist system. Based on this technology, a read only memory (ROM) disc with a recording capacity of 25.2 GB on a 120-mm-diameter surface was mastered at a high recording speed of 4.92 m/s. The disc showed a reasonable jitter value of 8.0% using a conventional equalizer, 4.6% using a limit equalizer and a push-pull signal using a conventional readout optical system of lambda = 405 nm and NA = 0.85.