Sidewall-sealed poly-buffered LOCOS isolation

摘要

This is a semiconductor device, comprising: a semiconductor body having an isolation region separating at least two active device regions; pad oxide layers disposed on said active regions; polysilicon layers disposed on said pad oxide layers; silicon nitride layers disposed on said polysilicon layers; and a sidewall seal disposed all along the perimeter of the active device regions to seal said active device regions against oxygen diffusion. The resulting field oxide isolation region has reduced oxide encroachment into the active moat region.