forming a gate structure straddling over a portion of a silicon germanium alloy fin having a first germanium content;

forming a non-doped epitaxial silicon source material on a first side of said gate structure and a non-doped epitaxial silicon drain material on a second side of said gate structure, said second side is opposite said first side, wherein said non-doped epitaxial silicon source material is spaced apart from said non-doped epitaxial silicon drain material by an entirety of said gate structure;

forming a dielectric liner material on said non-doped epitaxial silicon source and drain materials and surrounding and in direct contact with physically exposed surfaces of said gate structure prior to performing a thermal mixing process;

performing said thermal mixing process, wherein said thermal mixing process converts a portion of said silicon germanium alloy fin and said non-doped epitaxial silicon source material into a silicon germanium alloy source structure having a second germanium content that is less than said first germanium content, converts another portion of said silicon germanium alloy fin and said non-doped epitaxial silicon drain material into a silicon germanium alloy drain structure having said second germanium content, and provides a tensile strained silicon germanium alloy fin portion having said first germanium content; and

introducing a dopant into said silicon germanium alloy source structure and into said silicon germanium alloy drain structure.