A semiconductor device, including a substrate, a first electrode layer, a functional layer, and a second electrode layer. The functional layer is located between the first electrode layer and the second electrode layer, and includes a first region and a second region having a C-shaped structure surrounding the first region. The C-shape structure opens toward a direction that is parallel with the substrate and away from the first region, that is, the C-shaped structure opens toward a distal side. The first region is made of at least germanium, and the second region includes a C-shaped ferroelectric layer and a C-shaped gate that are sequentially stacked. The C-shaped ferroelectric layer serves as a memory layer of the memory device.