Oxide for semiconductor layer of thin film transistor, sputtering target, and thin film transistor
Disclosed is an oxide for a semiconductor layer of a thin film transistor, which, when used in a thin film transistor that includes an oxide semiconductor in the semiconductor layer, imparts good switching characteristics and stress resistance to the transistor. Specifically disclosed is an oxide for a semiconductor layer of a thin film transistor, which is used for a semiconductor layer of a thin film transistor and contains at least one element selected from the group consisting of In, Ga and Zn and at least one element selected from the group X consisting of Al, Si, Ni, Ge, Sn, Hf, Ta and W.
1. A sputtering target for forming an oxide, the sputtering target comprising
In, Ga, and Zn; and
at least one element selected from the group X consisting of Si, Ni, Hf, Ta, and W,
wherein
the sputtering target does not comprise Sn,
when the sputtering target comprises Si as the element of the group X, Si/(In+Ga+Zn+Si)×100=2.0 to 15 at %;
when the sputtering target comprises Ni as the element of the group X, Ni/(In+Ga+Zn+Ni)×100=0.1 to 5 at %;
when the sputtering target comprises Hf as the element of the group X, Hf/(In+Ga+Zn+Hf)×100=2.0 to 10 at %;
when the sputtering target comprises Ta as the element of the group X, Ta/(In+Ga+Zn+Ta)×100=2.0 to 10 at %; and
when the sputtering target comprises W as the element of the group X, W/(In+Ga+Zn+W)×100=2.0 to 10 at %.
2. The sputtering target according to claim 1 , comprising
In, Ga, Zn, and Si,
wherein Si/(In+Ga+Zn+Si)×100=2.0 to 15 at %.
3. The sputtering target according to claim 1 , comprising
In, Ga, Zn, and Ni,
wherein Ni/(In+Ga+Zn+Ni)×100=0.1 to 5 at %.
4. The sputtering target according to claim 1 , comprising
In, Ga, Zn, and Hf,
wherein Hf/(In+Ga+Zn+Hf)×100=2.0 to 10 at %.
5. The sputtering target according to claim 1 , comprising
In, Ga, Zn, and Ta,
wherein Ta/(In+Ga+Zn+Ta)×100=2.0 to 10 at %.
6. The sputtering target according to claim 1 , comprising
In, Ga, Zn, and W,
wherein W/(In+Ga+Zn+W)×100=2.0 to 10 at %.