Patent ID: 8889564

Claim:
A method of forming a semiconductor structure comprising: forming a mandrel structure on first portion of a surface of a substrate semiconductor layer; forming an epitaxial semiconductor layer on a second portion of said surface of said substrate semiconductor layer; forming a first dielectric spacer on sidewalls of said mandrel structure and on portions of a top surface of said epitaxial semiconductor layer; recessing physically exposed portions of said epitaxial semiconductor layer employing said first dielectric spacer as an etch mask to form recessed portions of said epitaxial semiconductor layer; forming a second dielectric spacer on sidewalls of said first dielectric spacer and sidewalls of recessed portions of said epitaxial semiconductor layer; and forming a ring-shaped semiconductor nanowire by etching said epitaxial semiconductor layer from said recessed portions, wherein a remaining portion of said epitaxial semiconductor layer is said ring-shaped semiconductor nanowire.