| 摘要 |
PURPOSE:To form a ROM which is capable of storing necessary information with small memory capacity by forming a common contact hole for a first transistor and providing the drains formed opposed to each other for a second transistor. CONSTITUTION:Each cell respectively forms one MOS transistors. A gate 3 is provided with equal width in common to the cells of rows. For example, the contact 4 inthe direction of column formed by aluminum are connected to the common terminals. The portion 5 (hatched portion) snadwiched by source 1 and drain 2 under the gate 3 is the channel portion and a channel resistance is set corresponding to sample value of voice signal by changing the width (Wi, j, Wi+j) of this channel 5. The wiring of contact 4 can be simplified and memory capacity can be enhanced by alternately providing the region where the contact 4 is used in common and the region where the drains are provided opposed to each other. |
