Target and process for its production, and method for forming a film having a high refractive index

• US 20010020586A1
• Filed: 12/05/2000
• Published: 09/13/2001
• Est. Priority Date: 08/23/1995
• Status: Active Grant

• Current Assignee: AGC Flat Glass North America Incorporated (AGC, Inc.)
• Original Assignee: Asahi Glass Company, Limited (AGC, Inc.)
• Inventors: Hayashi, Atsushi, Sasaki, Kenichi, Oyama, Takuji, Mitsui, Akira, Osaki, Hisashi, Kida, Otojiro, Suzuki, Eri
• Granted Patent: US 6,334,938 B2
• Time in Patent Office: Days
• US Class Current: 204/298.13
• CPC Class Codes: C23C 14/083 of refractory metals or yttrium
• CPC Class Codes: C23C 14/3414 Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy
• CPC Class Codes: C23C 4/02 Pretreatment of the material to be coated, e.g. for coating on selected surface areas
• CPC Class Codes: C23C 4/11 Oxides

Abstract

A sputtering target comprising a substrate and a target material formed on the substrate, wherein the target material comprises a metal oxide of the chemical formula MO_x as the main component, wherein MO_x is a metal oxide which is deficient in oxygen as compared with the stoichiometric composition, and M is at least one metal selected from the group consisting of Ti, Nb, Ta, Mo, W Zr and Hf, a process for its production, and a method for forming a film having a high refractive index.

Claims

1. A sputtering target comprising a substrate and a target material formed on the substrate, wherein the target material-comprises a metal oxide of the chemical formula MO_x as the main component, wherein MO_x is a metal oxide which is deficient in oxygen as compared with the stoichiometric composition, and M is at least one metal selected from the group consisting of Ti, Nb, Ta, Mo, W, Zr and Hf.

2. The sputtering target according to

claim 1

, wherein in said MO_x, M is Nb and/or Ta, and x is within a range of 2<

x<

2.5.

3. The sputtering target according to

claim 1

, wherein in said MO_x, M is Mo and/or W, and x is within a range from 2<

x<

3.

4. The sputtering target according to

claim 1

, wherein in said MO_x, M is at least one metal selected form the group consisting of Ti, Zr and Hf, and x is within a range of 1<

x<

2.

5. The sputtering target according to any one of

claims 1

to

4

, wherein the target material has a resistivity of at most 10 Ω

cm at room temperature.

11. A method for forming a film having a high refractive index by sputtering, wherein, as a sputtering target, the sputtering target as defined in any one of

claims 1

to

5

is used.

6. A process for producing a sputtering target, which comprises forming an undercoat made of a metal or alloy on a substrate, and forming a ceramic layer as a target material on the undercoat, wherein the ceramic layer as a target material is formed by plasma spraying wherein a ceramic powder which is made in a semi-molten state in a high temperature plasma gas in a reducing atmosphere, is transported and deposited onto the undercoat by the plasma gas, and, as the target material, a target material comprising a metal oxide of the chemical formula MO_x as the main component, is used, wherein MO_x is a metal oxide which is deficient in oxygen as compared with the stoichiometric composition, and M is at least one metal selected from the group consisting of Ti, Nb, Ta, Mo, W, Zr and Hf.

7. The process for producing a sputtering target according to

claim 6

, wherein, as the undercoat, a layer having a thermal expansion coefficient intermediate between the thermal expansion coefficient of the ceramic layer and the thermal expansion coefficient of the substrate, and/or a layer having a thermal expansion coefficient close to the thermal expansion coefficient of the ceramic layer, is used.

8. The process for producing a sputtering target according to

claim 6

, wherein the plasma spraying is water plasma spraying.

9. The process for producing a sputtering target according to

claim 6

, wherein a cylindrical substrate is used as the substrate.

10. The process for producing a sputtering target according to

claim 6

, wherein a surface-roughened substrate is used as the substrate.