| 摘要 |
PROBLEM TO BE SOLVED: To widen a charge storage area by forming a transfer transistor on a substrate and electrically connecting one of the source/drain regions of the transfer transistor to a charge storage capacitor. SOLUTION: A storage electrode of a charge storage capacitor in a DRAM has trunk-polysilicon layers 26a, 26b and branch polysilicon layers 40a, 40b, each having an L-shape in cross section. The trunk-polysilicon layers 26a, 26b, each having a T-letter shape in cross section, are electrically connected to drain regions 16a, 16b of a transfer transistor in the DRAM, respectively. Each of the branch-polysilicon layers 40a, 40b generally has a hollow cylindrical shape and its horizontal cross section may be circular, rectangular, or the like according to the shape of each of deposition layers 30a, 32a, and 30b, 32b. The branch polysilicon layers 40a, 40b extend vertically upward from the top face of the trunk polysilicon layers 26a, 26b and then extend outwardly in the horizontal direction. |
