| 摘要 |
PURPOSE:To contrive the increase in integration and the improvement in reliability by a method wherein a means of preventing the diffusion of electrons is provided around a diffused layer which is the output terminal of a substrate bias generation circuit. CONSTITUTION:The titled device is provided with a groove 6 in a substrate 1 as the means of preventing the diffusion of electrons, so that it may surround an n<+> type layer 5 which is the output terminal of the substrate bias generation circuit 4. Setting the depth of the groove 6 at a suitable value makes the groove 6 serve as a barrier against the diffusion of electrons injected out of the n<+> type layer 5 into the substrate 1. As a result, they are effectively prevented from reaching a diffused electron memory cell array region 9 in the substrate. In practical use, when the groove 6 is deepened about twice as much as the layer 5 or more than it, the diffusion of electrons can be prevented much effectively, and the distance X between the memory cell array 9 and the substrate bias generation circuit 4 can be largely reduced. Besides, the malfunction of peripheral circuits due to the diffusion of electrons from said generation circuit can be prevented. |
