Sputtering target of dielectrics having high strength and a method for manufacturing same

• US 6,176,986 B1
• Filed: 05/27/1997
• Issued: 01/23/2001
• Est. Priority Date: 05/27/1996
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Materials Corporation
• Original Assignee: Mitsubishi Materials Corporation
• Inventors: Watanabe, Kazuo, Mishima, Akifumi
• Primary Examiner(s): Nguyen, Nam
• Assistant Examiner(s): Cantelmo, Gregg
• Application Number:
  US08/863,194
• Time in Patent Office: 1,337 Days
• Field of Search: 296/00, 298/40, 29/253.5, 427/394, 427/252, 427/421, 427/99, 423/598, 204/192.12, 204/192.15, 204/298.12, 204/298.13, 204/192.18, 118/715, 252/62.9 R, 501/137, 501/138, 501/139, 419/48, 419/49, 419/19
• US Class Current: 204/298.13
• CPC Class Codes: C04B 35/465 based on alkaline earth metal titanates
• CPC Class Codes: C23C 14/3414 Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy
• CPC Class Codes: H01L 21/02197 the material having a perovskite structure, e.g. BaTiO3
• CPC Class Codes: H01L 21/31691 with perovskite structure

Abstract

A dielectric sputtering target of high strength comprising a sintered barium, strontium titanate body, which is oxygen deficient, of the formula: Ba_1-xSr_xTiO_3-y, wherein 0<x<1 and 0<y≦0.03, the sintered body having a mean grain size of 0.3 to 5 μm, a maximum grain size of 20 μm or less, a relative density of 95% to 99%, a purity of 4N or more, a K content of 1 ppm or less, a Na content of 2 ppm or less, an Al content of 5 ppm or less, a Si content of 20 ppm or less, an Fe content of 2 ppm or less and a mean flexural strength of 150 MPa or more.

Claims

1. A dielectric sputtering target comprising:

a sintered barium, strontium titanate body, which is oxygen deficient, of the formula;

Ba_1-xSr_xTiO_3-y, wherein 0<

x<

1 and 0<

y≦

0.03, said sintered body having a mean grain size of 0.3 to 5 μ

m, a maximum grain size of 20 μ

m or less, a relative density of 95% to 99%, a purity of 4N or more, a K content of 1 ppm or less, a Na content of 2 ppm or less, an Al content of 5 ppm or less, a Si content of 20 ppm or less, an Fe content of 2 ppm or less and a mean flexural strength of 150 MPa or more.

2. A method for producing a dielectric sputtering target of a sintered (barium, strontium) titanate body, which is oxygen deficient, and which has the formula:

Ba_1-xSr_xTiO_3-y, wherein 0<

×

x<

1 and 0<

y≦

0.03, the sintered body having a mean grain size of 0.3-5 μ

m, a maximum grain size of 20 μ

m or less, a relative density of 95-99%, a purity of 99.99% or more, a K content of 1 ppm or less, a Na content of 2 ppm or less, and Al content of 5 ppm or less, a Si content of 20 ppm or less, an Fe content of 2 ppm or less and a mean flexural strength of 150 MPa or more, comprising;

hot-press sintering a powdered material of the formula;

Ba_1-xSr_xTiO_3.00, wherein 0<

x<

1 having a mean primary particle size of 1 μ

m or less at a sintering temperature of 1100-1300°

C. for a sintering time of 1-10 hours at a maximum temperature under a pressure of 10 MPa to 50 MPa in a vacuum or in an atmosphere of an inert gas.

3. A dielectric sputtering target comprising:

a sintered barium, strontium titanate body, which is oxygen deficient, of the formula;

Ba_1-xSr_xTiO_2.99-2.97, wherein 0<

x<

1, said sinted body having a mean grain size of 0.3-5 μ

m, a maximum grain size of 20 μ

m or less, a relative density of 95-99%, a purity of 4N or more, a K content of 1 ppm or less, a Na content of 2 ppm or less, and Al content of 5 ppm or less, a Si content of 20 ppm or less, an Fe content of 2 ppm or less and a mean flexural strength of 150 MPa or more.

4. A dielectric sputtering target comprising:

a sintered barium, strontium titanate body, which is oxygen deficient, of the formula;

Ba_1-xSr_xTiO_3-y, wherein 0<

x<

1 and 0<

y<

0.03, said sintered body having a mean grain size of 0.3-5 μ

m, a maximum grain size of 20 μ

m or less, a relative density of 95-99%, a purity of 4N or more, a K content of 1 ppm or less, a Na content of 2 ppm or less, and Al content of 5 ppm or less, a Si content of 20 ppm or less, an Fe content of 2 ppm or less and a mean flexural strength of 150 MPa or more.

5. A dielectric sputtering target comprising:

a sintered barium, strontium titanate body, which is oxygen deficient, of the formula;

Ba_1-xSr_xTiO_2.99-2.97, wherein 0<

x<

1, said sintered body having a mean grain size of 0.3-5 μ

m, a maximum grain size of 20 μ

m or less, a relative density of 95-99%, a purity of 4N or more, a K content of 1 ppm or less, a Na content of 2 ppm or less, and Al content of 5 ppm or less, a Si content of 20 ppm or less, an Fe content of 2 ppm or less and a mean flexural strength of 150 MPa or more.

6. A dielectric sputtering target comprising:

a sintered barium, strontium titanate body, which is oxygen deficient, of the formula;

Ba_1-xSr_xTiO_2.99-2.98, wherein 0<

x<

1, said sintered body having a mean grain size of 0.3-5 μ

m, a maximum grain size of 20 μ

m or less, a relative density of 95-99%, a purity of 4N or more, a K content of 1 ppm or less, a Na content of 2 ppm or less, and Al content of 5 ppm or less, a Si content of 20 ppm or less, an Fe content of 2 ppm or less and a mean flexural strength of 150 MPa or more.