摘要 |
<p>A method of forming a watermark image in a hybrid optical master disc is disclosed. The method includes the steps of projecting a watermark image on a photoresist layer of the master disc; exposing a spiral wobbled groove and depressions in the groove in a ROM area thereof; developing the exposed areas of the photoresist layer to provide physical depressions, a physical spiral wobbled groove and a physical watermark image; forming a stamper having the physical features of the developed photoresist layer; replicating the physical features in a plastic substrate with the stamper; and coating the plastic substrate with a recording medium structure to provide a hybrid optical disc having a watermark image in the plastic substrate under the recording medium structure.</p> |