Semiconductor structure with a doped region between two deep trench isolation structures

摘要

The density of a transistor array is increased by forming one or more deep trench isolation structures in a semiconductor material. The deep trench isolation structures laterally surround the transistors in the array. The deep trench isolation structures limit the lateral diffusion of dopants and the lateral movement of charge carriers.

主权项

1. A semiconductor structure comprising:
a substrate having a first conductivity type and a top surface; an epitaxial layer having the first conductivity type, a bottom surface that touches the top surface of the substrate, and a top surface; a buried region having a second conductivity type, the buried region touching and lying below a portion of the epitaxial layer; a shallow trench isolation structure formed in the top surface of the epitaxial layer to extend down into the epitaxial layer; an inner deep trench isolation structure formed in the top surface of the epitaxial layer to extend down into the epitaxial layer, the inner deep trench isolation structure laterally surrounding the shallow trench isolation structure; an outer deep trench isolation structure formed in the top surface of the epitaxial layer to extend down into the epitaxial layer, the outer deep trench isolation structure laterally surrounding the inner deep trench isolation structure; and a doped region formed in the top surface of the epitaxial layer to extend down into the epitaxial layer and below the inner and outer deep trench isolation structures to touch the buried region, the doped region having the second conductivity type, touching the inner and outer deep trench isolation structures, and laterally surrounding the portion of the epitaxial layer.