| 摘要 |
PURPOSE:To control diffusion of a noise charge and to prevent a malfunction of a device, by forming an electrode of a layer high in its charge mobility on the periphery of a device to be protected. CONSTITUTION:A source diffusion layer and a drain diffusion 1 are made to be first layers, and a well diffusion layer 2 is made to be a second layer. An electrode of a third layer 3 lower in its resistance than the second layer 2 is made to be of the same type as the well and it is made high in its impurity concentration so as to have a contact 4. A stay of noise charges can be remarkably relaxed in the well 2 in this way. Since diffusion of charges is hence promoted at a low resistance part 3 and the stay of noise charges can be suppressed, this device can be prevented from malfunctioning caused by the noise charges. |
