Sputtering target and manufacturing method therefor, and optical recording medium and manufacturing method therefor

• US 7,488,526 B2
• Filed: 11/20/2006
• Issued: 02/10/2009
• Est. Priority Date: 11/22/2005
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Hayashi, Yoshitaka, Fujii, Toshishige, Fujiwara, Masayuki, Sasa, Noboru
• Primary Examiner(s): MULVANEY, ELIZABETH EVANS
• Application Number:
  US11/602,629
• Publication Number:
  US 20070114129A1
• Time in Patent Office: 813 Days
• Field of Search: 428/64.4, 428/64.5, 430/270.13, 204/192.1
• US Class Current: 428/64.4
• CPC Class Codes: C23C 14/085 of iron group metals
• CPC Class Codes: C23C 14/086 of zinc, germanium, cadmium, indium, tin, thallium or bismuth
• CPC Class Codes: C23C 14/3414 Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy
• CPC Class Codes: G11B 7/266 Sputtering or spin-coating layers sputtering in general C23C14/24; spin-coating in general B05D1/005

Abstract

To provide a sputtering target used for the formation of a recording layer of a recordable optical recording medium, wherein the sputtering target contains Bi and Fe and the packing density of the sputtering target is greater than 96%, and a recordable optical recording medium manufactured by using the sputtering target, which the recordable optical recording medium is capable of high-density recording even in the blue laser'"'"'s wavelength range.

Claims

1. A sputtering target comprising:

Bi and Fe,

wherein the packing density of the sputtering target is greater than 96%, and

wherein the sputtering target is used for the formation of a recording layer of a recordable optical recording medium.

2. The sputtering target according to claim 1, wherein the sputtering target comprises Bi, Fe, and O, and the packing density of the sputtering target is greater than 96%.

10. The sputtering target according to claim 1, wherein the sputtering target comprises at least one of a shape, a structure and a composition for allowing a magnetic flux to leak from a target surface side, and wherein magnetron sputtering can be applied.

11. The sputtering target according to claim 10, wherein the sputtering target comprises a non-ferromagnetic compound.

12. The sputtering target according to claim 10, wherein Fe is contained as a ternary compound of BiFeO.

13. The sputtering target according to claim 10, wherein Fe is contained as α

-Fe₂O₃.

14. The sputtering target according to claim 10, wherein the sputtering target comprises a shape for allowing a magnetic flux to leak from the target surface side.

16. The sputtering target according to claim 1, wherein among the elements the Bi proportion is 28 atomic % or more.

3. A sputtering target comprising:

Bi and Fe,

wherein the specific resistance of the sputtering target is 10 Ω

cm or less, and

wherein the sputtering target is used for the formation of a recording layer of a recordable optical recording medium.

4. The sputtering target according to claim 3, wherein the sputtering target comprises Bi, Fe and O, and further comprises a substance for imparting conductivity.

5. The sputtering target according to claim 3, wherein the sputtering target comprises a compound where oxygen is reduced compared to a stoichiometric composition.

6. The sputtering target according to claim 3, wherein among elements other than oxygen, the proportion of Bi is 28 atomic % or more.

7. The sputtering target according to claim 3, wherein the sputtering target comprises at least one of Bi and Fe, both of which are in a metallic state.

8. The sputtering target according to claim 3, wherein the sputtering target comprises at least one metal other than Bi and Fe.

9. The sputtering target according to claim 3, wherein the packing density is greater than 96%.

15. A method for manufacturing a sputtering target by means of sintering method,

wherein the sputtering target is used for the formation of a recording layer of a recordable optical recording medium and comprises Bi and Fe, and the packing density of the sputtering target is greater than 96%.

17. The method of claim 15, wherein said sintering method comprises using raw materials including an element that imparts conductivity to the sputtering target.