Effect of substrate and metal layer deformation on recording characteristics of recordable discs with metallic thin film

Abstract

Compact disc-recordable (CD-R) and digital versatile disc-recordable (DVD-R) discs were fabricated with a polycarbonate substrate, metallic thin film, organic buffer layer, reflective layer, and protective layer. Recording characteristics of a CD-R disc at various recording speeds, from Ix to 8x, were evaluated, and the deformation shapes of each layer after recording were investigated and compared with the DVD-R disc. The relationship between deformation and recording characteristics was studied and interpreted by numerical calculation. The modulated amplitude of recorded signals is increased as the recording speed increases, owing to the increase in decomposition of the buffer layer, which resulted from the localization of heat on the metallic thin film. On the basis of these results, a DVD-R disc with metallic thin film is expected to have better recording characteristics at a higher recording speed. (C) 2001 Optical Society of America.