| 摘要 |
PURPOSE:To make the holding characteristic of a digit line excellent and to make the reading speed of an ROM quick, by adding the same capacitor as that attached to an ON-bit Tr to an OFF-bit Tr of a memory cell and also to a digit line. CONSTITUTION:A capacitor C1 of a Tr 1 is a capacitor for a drain diffused layer in a memory cell. A capacitor C'1 of a Tr 2 is a capacitor for a digit line through a thin oxide film on a drain diffused layer of the Tr 2. The capacitance of the C'1 can be made the same as the capacitance of the C1 by controlling the thickness of a thin oxide film. In this memory device, the capacitor C'1, whose value is about the same as that of the drain capacitor C1 on of the ON-bit memory, is added to the OFF bit memory (Tr 2, n). |
