Aluminum alloy film, method of producing the same, and thin film transistor

1. An aluminum alloy film formed by a sputtering method on a substrate, the aluminum alloy film comprising:

an Al pure metal that includes Zr, Sc, and at least one type of a first additive element selected from the group consisting of Mo, Y, Nb, and Ti, the first additive element forming intermetallic compounds of Al;

Mn, Si, and at least one type of a second additive element selected from the group consisting of Mg and Ag, the second additive element being dissolved in Al; and

at least one type of a third additive element selected from the group consisting of Ce, Nd, La, and Gd;

a total content of Zr, Sc, and the first additive element being 0.01 atomic % or more and 1.0 atomic % or less,

a total content of Mn, Si, and the second additive element being 0.2 atomic % or more and 3.0 atomic % or less, and

a total content of the third additive element being 0.1 atomic % or more and 1.0 atomic % or less.

2. The aluminum alloy film according to claim 1 , wherein

the aluminum alloy film has bending resistance that can withstand bending in a case of being bent to a bending radius of 1 mm.

3. The aluminum alloy film according to claim 1 , wherein dry etching and wet etching of the aluminum alloy film are possible under the conditions that:

as the dry etching, an etching gas is a mixed gas of Cl 2 (50 sccm)/Ar (20 sccm), an etching pressure is 1.0 Pa, and discharge power is 400 W in a case where the substrate bias power is 200 W; and

as the wet etching solution, a mixed solution of phosphoric acid/nitric acid/acetate/water is used and a liquid temperature is 40° C.

4. The aluminum alloy film according to claim 1 , wherein

a surface roughness P−V value is 50 nm or less.

5. The aluminum alloy film according to claim 1 , wherein

specific resistance is 10 μ 106 ·cm or less.

6. A thin film transistor, comprising:

a gate electrode including an aluminum alloy film,

the aluminum alloy film including:

an Al pure metal that includes Zr, Se, and at least one type of a first additive element selected from the group consisting of Mo, Y, Nb, and Ti, the first additive element forming intermetallic compounds of Al;

Mn, Si, and at least one type of a second additive element selected from the group consisting of Mg and Ag, the second additive element being dissolved in Al; and

at least one type of a third additive element selected from the group consisting of Ce, Nd, La, and Gd,

a total content of Zr, Sc, and the first additive element being 0.01 atomic % or more and 1.0 atomic % or less,

a total content of Mn, Si, and the second additive element being 0.2 atomic % or more and 3.0 atomic % or less, and

a total content of the third additive element being 0.1 atomic % or more and 1.0 atomic % or less.

7. A production method of an aluminum alloy film, the production method comprising:

including Zr, Sc, and at least one type of a first additive element selected from the group consisting of Mo, Y, Nb, and Ti;

including Mn, Si, and at least one type of a second additive element selected from the group consisting of Mg and Ag;

further including at least one type of a third additive element selected from the group consisting of Ce, Nd, La, and Gd;

by a sputtering method using an Al alloy target in an Al pure metal; and

producing an aluminum alloy film having

a total content of Zr, Sc, and the first additive element of 0.01 atomic % or more and 1.0 atomic % or less on a substrate, the first additive element forming intermetallic compounds of Al,

a total content of Mn, Si, and the second additive element of 0.2 atomic % or more and 3.0 atomic % or less on a substrate, the second additive element being dissolved in Al, and

a total content of the third additive element being 0.1 atomic % or more and 1.0 atomic % or less.