Patent ID: 8829512

Claim:
A semiconductor device comprising: a substrate; a first insulating film over the substrate; a gate electrode over the first insulating film; a gate insulating film over the gate electrode; an oxide semiconductor film over the gate insulating film, the oxide semiconductor film comprising a first oxide semiconductor region and a pair of second oxide semiconductor regions; a source electrode and a drain electrode over the oxide semiconductor film; a second insulating film over the oxide semiconductor film and between the source electrode and the drain electrode; and a third insulating film over the source electrode, the oxide semiconductor film, the second insulating film, and the drain electrode, wherein the oxide semiconductor film comprises indium, gallium, and zinc, wherein the first oxide semiconductor region is between the pair of second oxide semiconductor regions, wherein the first oxide semiconductor region comprises a crystalline region comprising c-axis alignment, wherein the second insulating film overlaps with the first oxide semiconductor region, wherein the third insulating film is in contact with each upper surface of the pair of second oxide semiconductor regions, wherein an edge of the gate electrode and edges of the source electrode and the drain electrode overlap with each other, and wherein the edges of the source electrode and the drain electrode and the first oxide semiconductor region do not overlap with each other.