| 摘要 |
PURPOSE:To protect a high level potential accumulated in a capacitor constituting a memory cell from free electrons, by forming the capacitor between a region, wherein an arranged body of memory cells is formed, and a region, wherein peripheral circuits are formed, connecting one electrode of the capacitor to the ground potential, thereby capturing the free electrons in a semiconductor substrate by the capacitor. CONSTITUTION:A memory cell is constituted by an access transistor and an MIS capacitor. The arranged body of the memory cell is formed in a region. A capacitor is formed between said region and a region, wherein peripheral circuits are formed. One electrode of the capacitor is connected to the ground potential. For example, the memory cells are formed in a region defined by an isolating insulating film 4'. The peripheral circuits are formed in a region defined by an isolating insulating film 4''. An impurity region 3' is formed in a region between the films 4' and 4''. The impurity regions 3' is made to face an electrode 7' through a capacitor insulating film 10'. A capacitor is formed by the impurity regions 3', the capacitor insulating film 10' and the electrode 7'. Thus, electrons freed from the peripheral circuits into a substrate are absorbed into an inverted layer, which is generated in the substrate beneath the electrode 7' that is connected to the ground potential. The electrons do not reach the memory cells. Therefore, information stored in the memory cells are not erased by the free electrons. |
