Reverse optical mastering for data storage disk replicas
View Patent ↗A data storage master disk and method of making a data storage master disk. The data storage disk master is for use in a data storage disk replication process. The data storage disk molding processes produces replica disks having a surface relief pattern with replica lands and replica grooves. The method includes providing a master substrate. The master substrate is at least partially covered with a layer of photosensitive material. A surface relief pattern having master lands and master grooves is recorded in the data storage disk master, including the steps of exposing and developing the photosensitive material is controlled to form master grooves extending down to a substrate interface between the master substrate and the layer of photosensitive material, such that the width of the master grooves at the substrate interface corresponds to a desired width of the replica lands.
1. A replica disk comprising:
a replica substrate including a first major surface and a second major surface, the first major surface including a surface pattern defined by lands and interrupted grooves,
wherein the surface pattern defines a track pitch that is less than 425 nanometers,
wherein tops of the lands define widths between 25 percent of the track pitch and 140 nanometers, and
wherein the grooves define depths between 20 and 120 nanometers.
2. The replica disk of claim 1 , wherein the widths of the tops of the lands are greater than 35 percent of the track pitch.
3. The replica disk of claim 1 , wherein the tops of the lands are substantially flat and coplanar.
4. The replica disk of claim 3 , wherein the widths of the tops of the lands are greater than 35 percent of the track pitch.
5. The replica disk of claim 1 , wherein the depths of the grooves are between 55 and 110 nanometers.
6. The replica disk of claim 5 , wherein the tops of the lands are substantially flat and coplanar.
7. The replica disk of claim 5 , wherein the widths of the tops of the lands are greater than 35 percent of the track pitch.
8. The replica disk of claim 7 , wherein the tops of the lands are substantially flat and coplanar.