Master disc for an optical disc and method for manufacturing the master disc

An apparatus for manufacturing a stamper of an optical disc, including

• a substrate having a main surface;
• a photoresist laminate including at least two photoresist layers wherein
• a first photoresist layer is formed on said main surface and a second photoresist layer formed on said first photoresist layer, and any additional photoresist layers are formed on a preceding layer;
• said photoresist laminate having a plurality of pits, each having a depth corresponding to the number of exposed photoresist layers;
• each said photoresist layer having a photosensitivity higher than the photosensitivity of at least one preceding photoresist layer;
• and
• a light source having a selectable beam intensity;
• wherein said light source operates substantially at an ultraviolet wavelength.

A method for manufacturing a master disc for a stamper of an optical disc, said method including steps of:

• forming a photoresist laminate including a first photoresist layer and a second photoresist layer consecutively formed on a master disc substrate, the second photoresist layer having a photosensitivity higher than the photosensitivity of the first photoresist layer;
• exposing, by a scanning light source, the photoresist laminate while selecting an intensity level from a set of preselected intensity levels of the scanning light source;
• and
• developing the photoresist laminate to form therein a first pit revealing the substrate and a second pit revealing the first photoresist layer;
• wherein said scanning light source operates substantially at an ultra-violet wavelength.