| 摘要 |
PROBLEM TO BE SOLVED: To inhibit fluctuation in electric characteristics and improve reliability in a semiconductor device having a transistor which has an oxide semiconductor.SOLUTION: A semiconductor device having a transistor which has: a gate electrode; a gate insulation film on the gate electrode; an oxide semiconductor film on the gate insulation film; a source electrode electrically connected to the oxide semiconductor film; and a drain electrode electrically connected to the oxide semiconductor film. The oxide semiconductor film has a first oxide semiconductor film on the gate electrode side and a second oxide semiconductor film on the first oxide semiconductor film. The first oxide semiconductor film has a first region in which an atomic ratio of In is greater than an atomic ratio of M (M represents Ti, Ga, Sn, Y, Zr, La, Ce, Nd or Hf). The second oxide semiconductor film has a second region in which an atomic ratio of In is smaller than that of the first oxide semiconductor film and the second region has a portion thinner than the first region.SELECTED DRAWING: Figure 1 |
