| 摘要 |
PURPOSE:To obtain a medium which satisfies the push-pull value, reflectance and modulation degree specified by CD standards by specifying an optical phase difference, film thickness of a light-absorbing layer in a land area and depth of a pregroove. CONSTITUTION:The pregroove and light-absorbing layer are formed so as to satisfy the relations expressed by formulae II, III and IV. In these formulae, dsub is the distance from the interface 8 between the light-absorbing layer 3 and a substrate 2 in a land area 7 formed on both sides of the pregroove 6 to the bottom of the interface 8 in the pregroove 6, dabs is the distance from the interface 9 between the light-absorbing layer 3 and light-reflecting layer 4 in the land area 7 to the bottom of the interface 9 in the pregroove 6. nsub is the real part of the complex refractive index of the substrate, nabs is the real part of the complex refractive index of the light-absorbing layer 3, is the wavelength of reproducing light L2, DELTAS expressed by formula I is the optical phase difference in reproducing light L2 reflected by the light-reflecting layer 4 in the pregroove 6 and in the land area 7, and dln is film thickness of the light-absorbing layer 3 in the land area 7. |
