| 摘要 |
PURPOSE:To prevent the punch through phenomenon between neighbouring cells, by constituting one capacitor of neighbouring memory cells of a dug groove type cell, and constituting the other capacitor of a stack type cell of multilayer polycrystalline silicon film. CONSTITUTION:In a substrate, a dug groove 6 is formed, in the inside of which a dug groove type cell composed of a diffusion layer 2a and a first polycrystalline silicon layer 4 is formed. Neighbouring with the groove type cell, a stack type cell composed of a first polycrystalline silicon layer 4 and a third polycrystalline layer 7 is formed. By this constitution, the punch through phenomenon wherein the depletion layers between neighbouring cells connect to each other and an electric path is formed, the vanishing of information charge, and the electric interference between the neighbouring cells caused by the puch through are prevented. |
