Oxide semiconductor and thin film transistor including the same
Disclosed are an oxide semiconductor and a thin film transistor (TFT) including the same. The oxide semiconductor may include a lanthanoid (Ln) added to zinc oxide (ZnO) and may be used as a channel material of the TFT.
1. An oxide semiconductor comprising a lanthanoid (Ln) added to a zinc oxide (ZnO)-based material,
wherein a composition ratio of the lanthanoid (Ln) with respect to a total content of the ZnO-based material and the lanthanoid (Ln) is about 0 atomic percentage (at %)<Ln(at %)≦15 at %, and
wherein a composition ratio of zinc (Zn) with respect to a total content of the ZnO-based material and the lanthanoid (Ln) is about 34.2 at %≦Zn(at %)<46.5 at %.
2. The oxide semiconductor of claim 1 , wherein the lanthanoid (Ln) comprises at least one selected from the group consisting of lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and mixtures thereof.
3. The oxide semiconductor of claim 1 , wherein the ZnO-based material comprises ZnO, indium-zinc oxide (IZO), or gallium-indium-zinc oxide (GIZO).
4. The oxide semiconductor of claim 1 , wherein the ZnO-based material comprises IZO and the lanthanoid (Ln) comprises lanthanum (La).
5. The oxide semiconductor of claim 4 , wherein a composition ratio of lanthanum (La) with respect to a total content of indium (In), zinc (Zn), and lanthanum (La) is about 0 atomic percentage (at %)<La(at %)≦11.4 at %.
6. The oxide semiconductor of claim 5 , wherein a composition ratio of indium (In) with respect to a total content of indium (In), zinc (Zn), and lanthanum (La) is about 53.5 at %<In(at %)≦55.5 at %.
7. The oxide semiconductor of claim 1 , further comprising:
a Group I element, a Group II element, a Group III element, a Group IV element, or a Group V element.
8. The oxide semiconductor of claim 1 , wherein the oxide semiconductor is amorphous.
9. The oxide semiconductor of claim 1 , wherein the oxide semiconductor is partially crystalline.
10. The oxide semiconductor of claim 1 , wherein the oxide semiconductor is crystalline.
11. An oxide thin film transistor (TFT) comprising:
a gate;
a channel configured to correspond with the gate and including an oxide semiconductor including a lanthanoid (Ln) added to a zinc oxide (ZnO)-based material;
a gate insulating layer between the gate and the channel; and
a source and a drain configured to contact both sides of the channel, respectively,
wherein a composition ratio of lanthanoid (Ln) with respect to a total content of the ZnO-based material and the lanthanoid (Ln) is about 0 atomic percentage (at %)<Ln(at %)≦15 at %, and
wherein a composition ratio of zinc (Zn) with respect to a total content of the ZnO-based material and the lanthanoid (Ln) is about 34.2 at %≦Zn(at %)<46.5 at %.
12. The TFT of claim 11 , wherein the lanthanoid (Ln) comprises at least one selected from the group consisting of lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and mixtures comprising at least one of the foregoing.
13. The TFT of claim 11 , wherein the ZnO-based material comprises ZnO, indium-zinc oxide (IZO), or gallium-indium-zinc oxide (GIZO).
14. The TFT of claim 11 , wherein the ZnO-based material comprises IZO and the lanthanoid (Ln) comprises lanthanum (La).
15. The TFT of claim 14 , wherein a composition ratio of lanthanum (La) with respect to a total content of indium (In), zinc (Zn), and lanthanum (La) is about 0 atomic percentage (at %)<La(at %)≦11.4 at %.
16. The TFT of claim 15 , wherein the composition ratio of indium (In) with respect to a total content of indium (In), zinc (Zn), and lanthanum (La) is about 53.5 at %<In(at %)≦55.5 at %.
17. The TFT of claim 11 , wherein the oxide semiconductor further comprises a Group I element, a Group II element, a Group III element, a Group IV element, or a Group V element.
18. The TFT of claim 11 , wherein the oxide semiconductor is amorphous.
19. The TFT of claim 11 , wherein the oxide semiconductor is partially crystalline.
20. The TFT of claim 11 , wherein the oxide semiconductor is crystalline.