Optical transparent film and sputtering target for forming optical transparent film

• US 6,528,442 B1
• Filed: 12/07/2000
• Issued: 03/04/2003
• Est. Priority Date: 01/12/1999
• Status: Expired due to Term

• Current Assignee: JX Nippon Mining & Metals Corporation (ENEOS Holdings, Inc.)
• Original Assignee: Nikko Materials Co., Ltd. (JX Metals Corp)
• Inventors: Takami, Hideo, Kuwano, Katsuo
• Primary Examiner(s): Sample, David
• Application Number:
  US09/719,018
• Time in Patent Office: 817 Days
• Field of Search: 501/41, 501/45, 501/46-49, 501/52, 501/73, 501/77, 501/134, 501/153, 501/154, 501/1, 204/192.22, 204/192.23, 204/192.29, 204/192.26, 428/64.4, 428/64.5, 428/64.6, 428/433, 428/450
• US Class Current: 501/41
• CPC Class Codes: C03C 17/245 by deposition from the vapour phase
• CPC Class Codes: C03C 2217/23 Mixtures
• CPC Class Codes: C03C 2218/154 by sputtering
• CPC Class Codes: C03C 2218/32 After-treatment
• CPC Class Codes: C23C 14/08 Oxides C23C14/10 takes precedence
• CPC Class Codes: C23C 14/10 Glass or silica
• CPC Class Codes: C23C 14/3414 Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy
• CPC Class Codes: G11B 2007/25706 containing transition metal elements (Zn, Fe, Co, Ni, Pt)
• CPC Class Codes: G11B 2007/25708 containing group 13 elements (B, Al, Ga)
• CPC Class Codes: G11B 2007/2571 containing group 14 elements except carbon (Si, Ge, Sn, Pb)
• CPC Class Codes: G11B 2007/25715 containing oxygen
• CPC Class Codes: G11B 7/243 comprising inorganic materials only, e.g. ablative layers
• CPC Class Codes: G11B 7/257 of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers
• CPC Class Codes: G11B 7/2578 consisting essentially of inorganic materials
• CPC Class Codes: G11B 7/26 Apparatus or processes specially adapted for the manufacture of record carriers

Abstract

To provide an optically transparent film containing 0.01 to 20% by weight glass forming oxide consisting of Nb₂O₅, V₂O₅, B₂O₃, SiO₂, and P₂O₆; 0.01 to 20% by weight Al₂O₃ or Ga₂O₃; and 0.01 to 5% by weight hard oxide of ZrO₂ and TiO₂ as required; balance being ZnO, and a sputtering target for forming such a film. This sputtering target reduces occurrence of particles during sputtering, decreases the number of interruption or discontinuance of sputtering to improve production efficiency, and forms a protective film for optical disks with large transmittance and low reflectance.

Claims

1. An optically transparent film, comprising:

0.01 to 20% by weight of at least one glass forming oxide including P₂O₅;

0.01 to 20% by weight of one of Al₂O₃ and Ga₂O₃, and

a balance being ZnO.

2. A sputtering target for forming an optically transparent film, comprising:

0.01 to 20% by weight of at least one glass forming oxide including P₂O₅; and

0.01 to 20% by weight of one of Al₂O₃ and Ga₂O₃,

a balance being ZnO.

3. An optically transparent film, comprising:

0.01 to 20% by weight of at least one glass forming oxide selected from a group consisting of Nb₂O₅ and V₂O₅;

0.01 to 20% by weight of Ga₂O₃, and

a balance being ZnO.

4. An optically transparent film, comprising:

0.01 to 20% by weight of at least one glass forming oxide selected from a group consisting of Nb₂O₅, V₂O₅, B₂O₃, SiO₂ and P₂O₅;

0.01 to 20% by weight of one of Al₂O₃ and Ga₂O₃;

0.01 to 5% by weight of a hard oxide including ZrO₂; and

a balance being ZnO.

5. A sputtering target for forming an optically transparent film, comprising:

0.01 to 20% by weight of at least one glass forming oxide selected from a group consisting of Nb₂O₅ and V₂O₅; and

0.01 to 20% by weight of Ga₂O₃,

a balance being ZnO.

6. A sputtering target for forming an optically transparent film, comprising:

0.01 to 20% by weight of at least one glass forming oxide selected from a group consisting of Nb₂O₅, V₂O₅, B₂O₃, SiO₂ and P₂O₅;

0.01 to 20% by weight of one of Al₂O₃ and Ga₂O₃;

0.01 to 5% by weight of a hard oxide including ZrO₂; and

a balance being ZnO.

7. An optical disc, comprising:

a recording layer on which information is written by irradiation of laser beams which cause crystallographic phase change of a structure of said recording layer and from which information is read by sensing a change in reflectance of said recording layer between said crystallographic phase changes of said structure; and

a pair of optically transparent protective films located on opposite sides of said recording layer to sandwich said recording layer therebetween, each of said optically transparent protective films having 0.01 to 20% by weight of at least one glass forming oxide selected from a group consisting of Nb₂O₅, V₂O₅, B₂O₃, SiO₂ and P₂O₅;

0.01 to 20% by weight of one of Al₂O₃ and Ga₂O₃; and

a balance of ZnO.