Butted SOI junction isolation structures and devices and method of fabrication

摘要

A structure, a FET, a method of making the structure and of making the FET. The structure including: a silicon layer on a buried oxide (BOX) layer of a silicon-on-insulator substrate; a trench in the silicon layer extending from a top surface of the silicon layer into the silicon layer, the trench not extending to the BOX layer, a doped region in the silicon layer between and abutting the BOX layer and a bottom of the trench, the first doped region doped to a first dopant concentration; a first epitaxial layer, doped to a second dopant concentration, in a bottom of the trench; a second epitaxial layer, doped to a third dopant concentration, on the first epitaxial layer in the trench; and wherein the third dopant concentration is greater than the first and second dopant concentrations and the first dopant concentration is greater than the second dopant concentration.

主权项

1. A structure, comprising:
a silicon layer on a buried oxide layer of a silicon-on-insulator substrate; a first gate electrode of a field effect transistor on a top surface of a gate dielectric layer formed on a top surface of said silicon layer and a second gate of a second field effect transistor on said top surface of said gate dielectric layer; a trench in said silicon layer between said first and second gate electrodes, said trench extending from a top surface of said silicon layer into said silicon layer, said trench not extending to said buried oxide layer; a doped region in said silicon layer between and abutting said buried oxide layer and a bottom of said trench, said doped region doped to a first dopant concentration, said doped region and said silicon layer doped opposite dopant types; a first epitaxial layer, doped to a second dopant concentration, in a bottom of said trench, said first epitaxial layer partially filling said trench; a second epitaxial layer, doped to a third dopant concentration, on said first epitaxial layer in said trench; and wherein said third dopant concentration is greater than said first and second dopant concentrations and said first dopant concentration is greater than said second dopant concentration.