| 摘要 |
<p>PROBLEM TO BE SOLVED: To sharpen the boundary lines between grooves, lands and pits and to decrease jitter errors when multiple pieces of information are recorded at a high density y prebaking a first photoresist layer at a temp. higher than for a second photoresist layer at the time of prebaking the first and second photoresist layers consisting of the same material. SOLUTION: The first photoresist layer 110 is formed at a thickness ofλ/4 (λ: the wavelength of a reproducing laser beam, n: the refractive index of a substrate) on a substrate 100 and is prebaked at 130 deg.C for 30 minutes. The second photoresist layer 120 of a thickness ofλ/6n is formed of the same material thereon and is prebaked at 110 deg.C to enhance photosensitivity. These layers are exposed to groove 101 patterns by the weak laser beam and the non- irradiated parts are formed as the lands 102. Next, the strong irradiation light is passed through the second layer 12 and the first layer 110 is exposed with the bit 103 patterns. The first and second layers 110, 120 are then etched, by which the master disk sharply formed with the grooves 101, the lands 102 and the pits 103 is obtd.</p> |
