METHOD OF WELL ISOLATION FOR SEMICONDUCTOR INTEGRATED DEVICE

摘要

The well isolation method using a trench structure in a semiconductor device having an N semiconductor substrate (21) and N and P types of wells (22,23) comprises forming trench structures on the border of the well (42,43) respectively, and applying the predetermined voltage to the wells and trenches so that the outwall of the trench has the same conduction type as the well adjacent to the trench have, thereby isolating the wells to prevent active regions from being short-circuited. The trench structure comprise an isolation film (27) formed on the inner wall of the trench and a high conductive trench node (28) filled on the inside of the trench.