| abstract |
An oxide semiconductor film which contains In, Ga and Sn at atomic ratios expressed by formula (1) 0.01 ≤ Ga/(In + Ga + Sn) ≤ 0.30, formula (2) 0.01 ≤ Sn/(In + Ga + Sn) ≤ 0.40 and formula (3) 0.55 ≤ In/(In + Ga + Sn) ≤ 0.98, while containing a rare earth element X at an atomic ratio expressed by formula (4) 0.03 ≤ X/(In + Ga + Sn + X) ≤ 0.25. |