Dielectric isolated fin with improved fin profile

A fin field effect transistor (finFET) comprising:

• a fin structure that is present on a dielectric surface, wherein a uniform tail region is present at an interface of the fin structure and dielectric surface;
• a gate structure present on a portion of the fin structure including a gate dielectric in contact with a channel portion of the fin structure;
• a gate sidewall spacer that has a compensatory strain that neutralizes strain in the underlying dielectric surface from impacting said fin structure;
• and
• a source region and a drain region on opposing sides of the channel portion of the fin structure.

A method for forming a fin structure comprising:

• forming a dielectric spacer on a sidewall of a plurality of fin structures, the fin structures overlying a substrate;
• forming a semiconductor spacer on a sidewall of the dielectric spacer;
• etching an exposed portion of the substrate to form a pedestal;
• forming a dielectric fill in a space between the adjacent fin structures;
• and
• annealing the semiconductor spacer and a portion of the plurality of fin structures that is present below a lower surface of the dielectric spacer, wherein said annealing the portion of the plurality of fin structures produces a first strain and said annealing the semiconductor spacer produces a second strain.