Patent ID: 9214553
Filing Date: 2015-12-15
Classification: H01L

Abstract:
1. A method of forming a FinFET device, comprising: forming a first epi semiconductor material on a semiconductor substrate; forming a second epi semiconductor material on said first epi semiconductor material; performing at least one trench etching process to define a plurality of trenches in said semiconductor substrate so as to thereby define an initial fin structure comprised of a portion of said semiconductor substrate, a portion of said first epi semiconductor material and a portion of said second epi semiconductor material, said initial fin structure having an axial length; forming a layer of insulating material so as to over-fill said trenches; with said layer of insulating material over-filling said trenches, performing a heating process to form a nanowire structure that is positioned between and spaced apart from said second epi semiconductor material portion and said semiconductor substrate portion of said initial fin structure, wherein said nanowire structure extends for the entire axial length of said initial fin structure and wherein said second epi semiconductor material constitutes the final fin structure of said FinFET device; after forming said nanowire structure, performing a first recess etching process to recess an upper surface of said layer of insulating material such that a portion, but not all, of said final fin structure is exposed; forming a gate structure above and around the exposed portion of said final fin structure; after forming said gate structure, performing a second recess etching process to further recess the previously recessed upper surface of said layer of insulating material such that said nanowire structure is exposed; with said gate structure remaining in position, performing at least one nanowire etching process to remove said nanowire structure and thereby define an under-fin cavity under said final fin structure; and substantially filling said under-fin cavity with a stressed material.