Optical information carrier

• US 5,790,512 A
• Filed: 11/25/1996
• Issued: 08/04/1998
• Est. Priority Date: 12/24/1993
• Status: Expired due to Term

• Current Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Hoevenaars, Albericus A. M., Put, Paul L. M.
• Primary Examiner(s): Neyzari, Ali
• Application Number:
  US08/755,614
• Time in Patent Office: 617 Days
• Field of Search: 369/275.4, 369/275.3, 369/275.2, 369/275.1, 369/116, 369/110, 369/44.32, 369/58, 369/112, 369/100, 369/109, 369/32, 369/54, 369/44.14, 369/44.41 , 369/44.26, 369/283, 369/288, 428/641, 428/64.2, 428/64.4
• US Class Current: 369/275.4
• CPC Class Codes: G11B 7/24085 Pits
• CPC Class Codes: G11B 7/261 Preparing a master, e.g. exposing photoresist, electroforming
• CPC Class Codes: Y10S 430/146 Laser beam

Abstract

A method for manufacturing optical information carriers, in which a photoresist layer (20) on a master disc (5) is exposed by a radiation beam (19). The intensity of the radiation beam is controlled by a modulator (14) and a control device (10) in such a manner that the exposure dose has a constant predetermined value over the length of a recorded area, which value is independent of the length of the area.

Claims

1. An optical information carrier comprising a substrate having information units stored thereon, in which the information units are stored on the substrate in the form of information areas each having a length, wherein the lengths of substantially all information areas deviate less than 50 nm from the lengths of the associated information units.

6. An optical information carrier according to claim 1, in which the information areas are pits in a layer of the optical information carrier.

2. An optical information carrier comprising a substrate having information units stored thereon, in which the information units are stored on the substrate in the form of information areas each having a length, wherein the difference between the lengths of the information areas and the lengths of the associated information units have a standard deviation of less than 10 nm.

7. An optical information carrier according to claim 2, in which the information areas are pits in a layer of the optical information carrier.

3. An optical information carrier comprising a substrate having information units stored thereon, in which the information units are stored on the substrate in the form of information areas, each having a length, and intermediate areas between adjacent information areas, each of said intermediate areas also having a length, wherein the lengths of substantially all intermediate areas deviate less than 50 nm from the distances between the associated information units.

8. An optical information carrier according to claim 3, in which the information areas are pits in a layer of the optical information carrier.

4. An optical information carrier comprising a substrate having information units stored thereon, in which the information units are stored on the substrate in the form of information areas, each having a length, and intermediate areas between adjacent information areas, each of said intermediate areas also having a length, wherein the differences between the lengths of the intermediate areas and the lengths of the associated information units have a standard deviation of less than 10 nm.

9. An optical information carrier according to claim 4, in which the information areas are pits in a layer of the optical information carrier.

5. An optical information carrier comprising a substrate having information units stored thereon, in which the information units are stored on the substrate in the form of information areas each having a width, characterized in that the spread in width of the information areas is smaller than 30 nm.

10. An optical information carrier according to claim 5, in which the information areas are pits in a layer of the optical information carrier.