Isolation structures for semiconductor devices

摘要

Isolation structures for isolating semiconductor devices from a substrate include floor isolation regions buried within the substrate and one or more trenches extending from a surface of the substrate to the buried floor isolation region.

主权项

1. An isolation structure formed in a semiconductor substrate of a first conductivity type, the substrate not including an epitaxial layer, the isolation structure comprising:
a first floor isolation region of a second conductivity type opposite to the first conductivity type submerged in the substrate; and a first plurality of dielectric filled trenches extending downward from a surface of the substrate and overlapping onto the first floor isolation region, the first plurality of dielectric filled trenches and the first floor isolation region electrically isolating a first pocket of the first conductivity type from the substrate; a second floor isolation region of the second conductivity type submerged in the substrate and laterally displaced from the first floor isolation region; a second plurality of dielectric filled trenches extending downward from the surface of the substrate and overlapping onto the second floor isolation region, the second plurality of dielectric filled trenches and the second floor isolation region electrically isolating a second pocket of the first conductivity type from the substrate; and a buried region of the first conductivity type having a doping concentration greater than a doping concentration of the substrate located laterally between the first floor isolation region and the second floor isolation region.