Prevention of contact to substrate shorts

摘要

Isolation trenches are etched through an active silicon layer overlying a buried oxide on a substrate into the substrate, and through any pad dielectric(s) on the active silicon layer. Lateral epitaxial growth of the active silicon layer forms protrusions into the isolation trenches to a lateral distance of at least about 5 nanometers, and portions of the isolation trenches around the protrusions are filled with dielectric. Raised source/drain regions are formed on portions of the active silicon layer including a dielectric. As a result, misaligned contacts passing around edges of the raised source/drain regions remain spaced apart from sidewalls of the substrate in the isolation trenches.

主权项

1. An integrated circuit structure that includes a transistor, comprising:
an isolation region filled with a dielectric material, the isolation region extending through an active semiconductor layer and through an overlying a buried oxide layer on a substrate and into the substrate, the active semiconductor layer being electrically isolated from the substrate by the buried oxide layer that is positioned between them; an epitaxial region of the active semiconductor layer protruding into a sidewall of the dielectric material in the isolation region to form a protrusion having a curved profile; a gate dielectic overlying the active semiconductor layer at location spaced away from the epitaxial region protrusion; a gate electrode overlying the gate dielectric; a source/drain region overlying and abutting in physical and electrical contact with the active semiconductor layer; and a conductive material being in physical and electrical contact with the source/drain region to form a source/drain contact.