| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor device having achieved miniaturization while suppressing the defect, and a highly reliable semiconductor device with the stable electric characteristics.SOLUTION: An insulating layer is provided with a convex structure. By having a channel formation region of an oxide semiconductor layer formed in contact with the convex structure, the channel formation region is extended in a three-dimensional direction (substrate vertical direction). This can achieve the miniaturization of the transistor and extend the effective channel length. In addition, a curved surface is formed at the upper corner part where the upper surface and the side surface of the convex structure intersect, and the oxide semiconductor layer is formed to include the crystal with the c-axis perpendicular to the curved surface. This can suppress the variation in electric characteristic of the oxide semiconductor layer due to the irradiation with the visible light or the UV light.SELECTED DRAWING: Figure 1 |
