Sputtering target and method for producing same

Patent metadata

Field	Value
Publication number	US-9988710-B2
Application number	US-201214352988-A
Country	US
Kind code	B2
Filing date	Jul 6, 2012
Priority date	Nov 1, 2011
Publication date	Jun 5, 2018
Grant date	Jun 5, 2018

Abstract

Provided are a sputtering target which has excellent machinability and is capable of forming a compound film that mainly contains Cu and Ga and a method for producing the sputtering target. The sputtering target of the present invention has a component composition that contains 15 to 40 at % of Ga, 0.1 to 5 at % of Bi, and the balance composed of Cu and unavoidable impurities with respect to all metal elements in the sputtering target. The method for producing the sputtering target includes a step of melting at least Cu, Ga and Bi as simple substances or an alloy that contains two or more of these elements at 1,050° C. or higher to produce an ingot.

First claim

What is claimed is:

1. A sputtering target for producing a solar cell having a component composition containing:
15 to 40 at % of Ga;
0.1 to 5 at % of Bi; and
the balance composed of Cu and unavoidable impurities with respect to all metal elements in the sputtering target, wherein
the sputtering target has a Bi-containing phase within crystal grains or at grain boundaries of an alloy phase mainly containing a Cu—Ga alloy,
the Bi-containing phase contains at least one of a Bi simple substance or an intermetallic compound containing 10 at % or greater of Bi,
the sputtering target has a density of 95% or greater, and
the average grain diameter of the Bi-containing phase is from 0.5 μm through 80 μm.

2. The sputtering target according to claim 1 , wherein the intermetallic compound containing 10 at % or greater of Bi contains Cu 5 Bi 2 .

3. The sputtering target according to claim 1 , wherein the average grain diameter of the metal phase in the sputtering target material is 100 μm or less.

4. A sputtering target for producing a solar cell having a component composition containing:
15 to 40 at % of Ga;
0.1 to 5 at % of Bi;
0.05 to 15 at % of Na; and
the balance composed of Cu and unavoidable impurities with respect to all metal elements in the sputtering target, wherein
Na is contained as an NaF compound, an Na 2 S compound, or an Na 2 Se compound, and
the sputtering target has a Bi-containing phase within crystal grains or at grain boundaries of an alloy phase mainly containing a Cu—Ga alloy,
the Bi-containing phase contains at least one of a Bi simple substance or an intermetallic compound containing 10 at % or greater of Bi,
the sputtering target has a density of 95% or greater, and
the average grain diameter of the Bi-containing phase is from 0.5 μm through 80 μm.

5. A method for producing the sputtering target according to claim 1 , the method comprising:
a step of melting at least Cu, Ga and Bi as simple substances or an alloy that contains two or more of these elements at 1,050° C. or higher to produce an ingot.

6. A method for producing the sputtering target according to claim 1 , the method comprising:
a step of producing a starting material powder that is obtained by pulverizing at least Cu, Ga and Bi as simple substances or an alloy that contains two or more of these elements; and
a step of subjecting the starting material powder to hot processing in a vacuum, in an inert atmosphere or in a reducing atmosphere,
wherein Ga contained in the starting material powder is contained in the form of a Cu—Ga alloy or in the form of a Ga—Bi alloy.

7. A method for producing the sputtering target according to claim 4 , the method comprising:
a step of producing a starting material powder that is obtained by preparing at least Cu, Ga and Bi as simple substances or an alloy that contains two or more of these.

Assignees

• Zhang Shoubin
• Shoji Masahiro
• Umemoto Keita
• Mitsubishi Materials Corp
• Solar Frontier Kk

Inventors

• Zhang Shoubin
• Shoji Masahiro
• Umemoto Keita

Classifications

• B22F9/082

  atomising using a fluid (using centrifugal force B22F9/10) · CPC title

• C22C9/00

  Alloys based on copper · CPC title

• C22C1/0425

  Copper-based alloys · CPC title

• B22F3/14

  simultaneously · CPC title

• C23C14/3414 Primary

  Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy · CPC title