| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical information recording medium having high S/N and high recording density and a process capable of producing such optical information recording medium. SOLUTION: Prepits 4 and guide grooves 5 for recording and reproducing light are fonned on a substrate 1 for the optical information recording medium. The cross-sectional shapes of the prepits 4 and the guide grooves 5 are formed to trapezoidal shapes both having a flat base surface or top surface. The depth or height of the prepits 4 is made higher than the depth or height of the guide grooves 5. Such substrate 1 may be formed by directly cutting the grooves corresponding to the prepits 4 and the guide grooves 5 on a master disk by, for example, a reactive ion etching device at the time of cutting of the master disk. |
