摘要 |
<p>An exposure master disc includes a photoresist laminate formed on a glass substrate. The photoresist laminate includes an i-line type, first photoresist layer and a g-line type, second photoresist layer consecutively formed on the substrate. The photoresist laminate is exposed by a scanning laser light while selecting the exposure power level, to thereby effectively expose the first and second photoresist layers or to effectively expose only the second photoresist layer. The resultant photoresist laminate has first pits revealing the substrate and second pits revealing the first photoresist layer, thereby forming two type of pits having different depths. Two type of pits and flat surface of the photoresist laminate provide three-valued data for a higher storage density. <IMAGE></p> |