Semiconductor device

摘要

A semiconductor device composed of analog circuits operated by multiple power supplies is provided with a structure which enables to reduce cross talk sufficiently. In the present semiconductor device, first and second transistors formed on the p-type silicon substrate are surrounded by third and fourth high concentration n-type buried layers extending beyond two trenches provided so as to separately surround the first and second transistors. An n-type layer is formed on these high concentration n-type layers, and first and second electrodes are formed on the n-type layer. Electric potentials of the third and fourth high concentration n-type layers are stabilized at a fixed value by the supply of power through the electrodes mounted on the these layers in order to prevent cross talk.