Forming facet-less epitaxy with self-aligned isolation

摘要

A method of forming a semiconductor structure may include preparing a continuous active layer in a region of the substrate and forming a plurality of adjacent gates on the continuous active layer. A first raised epitaxial layer may be deposited on a recessed region of the continuous active layer between a first and a second one of the plurality of gates, whereby the first and second gates are adjacent. A second raised epitaxial layer may be deposited on another recessed region of the continuous active layer between the second and a third one of the plurality of gates, whereby the second and third gates are adjacent. Using a cut mask, a trench structure is etched into the second gate structure and a region underneath the second gate in the continuous active layer. The trench is filled with isolation material for electrically isolating the first and second raised epitaxial layers.

主权项

1. A method of forming a semiconductor structure on a substrate, the method comprising:
preparing a continuous active layer in a region of the substrate; forming a plurality of gates on top of the continuous active layer of the substrate; depositing a first raised epitaxial layer on a first recessed region of the continuous active layer, the first recessed region located between a first and a second one of the plurality of gates, wherein the first and the second one of the plurality of gates are adjacent; depositing a second raised epitaxial layer on a second recessed region of the continuous active layer, the second recessed region located between the second and a third one of the plurality of gates, wherein the second and the third one of the plurality of gates are adjacent; etching, using a cut mask, a trench structure into the second one of the plurality of gate structures and a region underneath the second one of the plurality of gates in the continuous active layer, the etching including a first etch for removing a cap nitride layer of the second one of the plurality of gates, and the etching including a second etch aligned with multilayered sidewalls of the second one of the plurality of gates, the multilayered sidewalls including a first spacer pair, a second spacer pair formed over the first spacer pair, a protective nitride layer formed over one of the second spacer pair, and a nitride liner formed only over another one of the second spacer pair, the first and the second raised epitaxial layer separated from the trench structure by the first and the second spacer pair, the protective nitride layer, and the nitride liner, the protective nitride layer and the nitride liner including two separately formed layers, wherein the protective nitride layer is formed prior to the formation of nitride liner; and filling the trench structure with isolation material, the isolation material electrically isolating the first raised epitaxial layer from the second raised epitaxial layer.