Semiconductor structure with dielectric-sealed doped region

摘要

Leakage current can be substantially reduced by the formation of a seal dielectric in place of the conventional junction between source/drain region(s) and the substrate material. Trenches are formed in the substrate and lined with a seal dielectric prior to filling the trenches with semiconductor material. Preferably, the trenches are overfilled and a CMP process planarizes the overfill material. An epitaxial layer can be grown atop the trenches after planarization, if desired.

主权项

1. A method comprising:
forming a recess in a substrate, the recess having a sidewall and a bottom; lining the recess with a dielectric material, the dielectric material being on the sidewall and bottom of the recess; forming a source/drain material in the recess, the dielectric material being disposed between the source/drain material and the substrate; after forming the source/drain material, forming a semiconductor layer over the source/drain material and over and adjoining a portion of the substrate proximate the recess; and after forming the semiconductor layer, forming a gate electrode directly over the semiconductor layer.