摘要 |
On a semiconductor substrate surface, a drain diffusion layer, which is in common to two transistors that make up a memory cell pair, is formed and source diffusion layers, for each of the transistors, respectively, are formed so as to sandwich the drain diffusion layer from both sides, a bit line is formed from a lower wiring layer and is connected to the drain diffusion layer, a source line is formed from the uppermost wiring layer, and the writing of information is performed by making a contact hole exist or non-existent immediately below the source line arranged from the uppermost wiring layer, in other words, by connection or non-connection of the source diffusion layer with the source line. By this arrangement, the TAT can be shortened and, since the capacitance of the bit line is not increased, high-speed operation with a short precharge time and discharge time for the bit line can be realized and the consumption power can be lessened.
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