| 摘要 |
PURPOSE:To contrive an increase in the integration density of a memory and an increase in the speed of the memory by a method wherein MOS transistors constituting the static random access memory are respectively formed three- dimensionally on first protruding parts and second protruding parts formed on these first protruding parts. CONSTITUTION:Two first protruding parts 4 are formed on a semiconductor substrate 3, second protruding parts 5 are respectively formed on these protruding parts 4 and first and second driver MOS transistors MOS1 and MOS2 are constituted by forming gate electrodes 6G1 and 6G2 on the sidewalls of the protruding parts 4. Moreover, third and fourth access MOS transistors MOS3 and MOS4 are constituted by forming gate electrodes 6G3 and 6G4 on the sidewalls of the protruding parts 5. In such a way, as the driver MOS transistor and the access MOS transistor, which are respectively one side of each memory cell, are superposed, the overall arrangement density of the memory cells on the substrate can be improved and the occupation areas of the memory cells can be reduced. Thereby, an increase in the speed of a semiconductor memory can be contrived along with the high integration density of the memory, that is, a reduction in the size of the memory. |
