| abstract |
A method for forming semiconductor fins with different fin heights and dielectric isolation from the underlying semiconductor substrate. The fins can be formed by etching an active epitaxial layer provided on the substrate. The intervening sacrificial epitaxial layer can be used to mold the growth of the active epitaxial layer, then remove it and backfill with an isolation dielectric layer. The isolation dielectric layer may be disposed between the bottom surface of the fins and the substrate, and may be deposited, for example, after an etching process used to define the fins. In different regions of the substrate, the dielectric isolation fins having different heights may have substantially coplanar top surfaces. |