Optical disk and method of producing the same

A method of producing an optical disk comprising the steps of:

• producing a first transparent substrate having a first surface and a second surface, by using a pre-produced first master stamper, the first surface being a beam incidence surface for a laser beam in recording or reproduction, and the second surface having a first concave section and a first convex section formed thereon, the first convex section having at least one first pre-pit;
• forming at least a first recording layer and a first reflective layer in order on the first substrate via the first concave and convex sections, thus producing a first intermediate disk structure;
• producing a second substrate, by using a mother stamper that is produced by transfer of a pre-produced second master stamper, the second substrate surface having a second concave section and a second convex section formed thereon, the second concave section having at least one second pre-pit;
• forming at least a second reflective layer and a second recording layer in order on the second substrate via the second concave and convex sections, thus producing a second intermediate disk structure;
• and
• bonding the first and second intermediate disk structures each other so that the first reflective layer faces the second recording layer.

A method of producing an optical disk comprising the steps of:

• producing a first transparent substrate having a first surface and a second surface, by using a pre-produced first master stamper, the first surface being a beam incidence surface for a laser beam in recording or reproduction, and the second surface having a first concave section and a first convex section formed thereon, the first convex section having at least one first pre-pit;
• forming at least a first recording layer and a first reflective layer in order on the first substrate via the first concave and convex sections and the first pre-pit, thus producing a first intermediate disk structure;
• applying a photoresist onto a glass substrate, followed by exposure and development to form a photoresist pattern on the photoresist, the photoresist pattern having a concave section and a first opening reaching a surface of the glass substrate, followed by first dry etching to a first surface portion of the glass substrate exposed through the first opening to form a first hole in the glass substrate;
• ashing the photoresist pattern to remove the concave section thereof, thus a second surface portion of the glass substrate being exposed, followed by second dry etching to the glass substrate through the second exposed surface and the first hole to form a second opening in the second exposed surface and to dig the first hole by the same depth as the second opening to from a second hole, followed by removal of the photoresist pattern, thus producing a glass master plate;
• producing a master stamper by transfer of the glass master plate, followed by production of a mother stamper by transfer of the master stamper, thus producing a second substrate having a second concave section and a second convex section formed thereon, the second concave section having at least second pre-pit, the second pre-pit being higher than the second convex section, by using the mother stamper;
• forming at least a second recording layer and a second reflective layer in order on the second substrate via the second concave and convex sections and the second pre-pit, thus producing a second intermediate disk structure;
• and
• bonding the first and second intermediate disk structures each other so that the first reflective layer faces the second recording layer.