| 摘要 |
PROBLEM TO BE SOLVED: To improve the degree of integration of SRAM cells by reducing the sizes of the SRAM cells, by constructing first and second drive transistors vertical to a semiconductor substrate of a first conductivity. SOLUTION: Parallel first and second active areas 70 and 70a are formed in a well formed in a semiconductor substrate having a first conductivity, by separating the areas 70 and 70a from each other by a field oxide film. Then the gate electrodes 75a of first and second access transistors are formed through a gate insulating film across the areas 70 and 70a. Furthermore, the gate electrode 75b of a first drive transistor is formed vertically to the semiconductor substrate having the first conductivity in the first active area 70 and, at the same time, the gate electrode 75c of a second drive transistor is formed vertically to the semiconductor substrate in the second active area 70a. Therefore, the degree of integration of cells can be improved, because the sizes of the cells can be reduced. |
