Method to introduce uniaxial strain in multigate nanoscale transistors by self aligned SI to SIGE conversion processes and structures formed thereby

摘要

Methods of forming a microelectronic structure are described. Embodiments of those methods may include providing a gate electrode comprising a top surface and first and second laterally opposite sidewalls, wherein a hard mask is disposed on the top surface, a source drain region disposed on opposite sides of the gate electrode, and a spacer disposed on the first and second laterally opposed sidewalls of the gate electrode, forming a silicon germanium layer on exposed portions of the top surface and the first and second laterally opposite sidewalls of the source drain region and then oxidizing a portion of the silicon germanium layer, wherein a germanium portion of the silicon germanium layer is forced down into the source drain region to convert a silicon portion of the source drain region into a silicon germanium portion of the source drain region.