Semiconductor device with isolation region

摘要

The semiconductor device, with a semiconductor substrate having an active region and an isolation region, comprises: (a) a first region present within the isolation region and having a surface level below that of the substrate (11); (b) a second region which is smaller and deeper than the first region and which adjoins the side faces of the first region; and (c) an insulation layer (19,22) introduced or buried within the first and second regions. Also claimed is a process for prodn. of the above device.