| 摘要 |
PURPOSE: To form plural kinds of pits varying in depth with good accuracy by a simple method. CONSTITUTION: This exposing master disk 10 has a substrate 52 having a flat surface 52a, a photoresist film 12 deposited on the surface 52a of this substrate 52 and many pits 14 bored in this photoresist film 12 by exposing and developing. This photoresist film 12 consists of two layers; photoresist films 121, 122. The pits 14 include two kinds; P11 , P12 ,... having the depth d1 from the surface 12a of the photoresist film 12 to the photoresist layer 121 and pits P21 , P22 ,... having depth d2 from the surface 12a of the photoresist film 12 to the photoresist layer 122. Two kinds of the pits varying in the depths are easily formed on the optical disk, by which writing of ternary data and increasing of the recording density thereof are made possible. |
