| abstract |
On the semiconductor substrate, the columnar semiconductor layer of the first conductive type formed on the semiconductor substrate, the source / drain diffusion layer of the second conductive type formed on the upper and lower portions of the columnar semiconductor layer, and on the side surfaces of the columnar semiconductor layer. The problem is solved by a semiconductor device including a memory cell having a gate electrode formed through a gate insulating film, and having a second conductive semiconductor layer, an insulator, or a cavity inside the columnar semiconductor layer. |