FORMING A FIN USING DOUBLE TRENCH EPITAXY

摘要

The present invention relates generally to semiconductor devices and more particularly, to a structure and method of forming a fin using double trench epitaxy. The fin may be composed of a III-V semiconductor material and may be grown on a silicon, silicon germanium, or germanium substrate. A double trench aspect ratio trapping (ART) epitaxy method may trap crystalline defects within a lower trench (i.e. a defective region) and may permit formation of a fin free of patterning defects in an upper trench (i.e. a fin mold). Crystalline defects within the defective region may be trapped via conventional aspect ratio trapping or three-sided aspect ratio trapping. Fin patterning defects may be avoided by utilizing a fin mold to grow an epitaxial fin and selectively removing dielectric material adjacent to a fin region.

主权项

1. A structure comprising:
a first dielectric layer on an upper surface of a substrate, wherein a lower trench extends a length of the substrate exposing a first upper surface of the substrate and a sidewall on one or more portions of the first dielectric layer, wherein the lower trench is surrounded by the first upper surface of the substrate at a bottom, a first sidewall of a first portion of the first dielectric layer and a second sidewall of, a second portion of the first dielectric layer opposite the first sidewall, an opening between the first dielectric layer and a third dielectric layer at two sides above the first sidewall and the second sidewall, and a defect trapping surface of the third dielectric layer at a top; a support layer on a second upper surface of the substrate, wherein a length of the support layer is perpendicular to the length of the lower trench; and the third dielectric layer contacting, and anchored to, a sidewall of the support layer, the third dielectric layer above, but not contacting, the first dielectric layer leaving the opening between the first dielectric layer and the third dielectric layer, wherein one or more upper trenches extend through the third dielectric layer down to the opening between the first dielectric layer and the third dielectric layer, wherein the one or more upper trenches are above the first dielectric layer but not above the lower trench.