METHODS OF FORMING FIN ISOLATION REGIONS UNDER TENSILE-STRAINED FINS ON FINFET SEMICONDUCTOR DEVICES

摘要

One illustrative method disclosed herein includes, among other things, forming a composite fin structure that is comprised of a first germanium-containing semiconductor material having a first concentration of germanium and a tensile-strained second semiconductor material (having a lesser germanium concentration) positioned on the first germanium-containing semiconductor material and performing a thermal anneal process to convert the first germanium-containing semiconductor material portion of the composite fin structure into a germanium-containing oxide isolation region positioned under the second semiconductor material that is a tensile-strained final fin for an NMOS FinFET device.

主权项

1. A method, comprising:
forming a composite fin structure that is at least partially positioned in a layer of insulating material formed above a semiconductor substrate material, said composite fin structure comprising a first germanium-containing semiconductor material having a first concentration of germanium positioned on a surface of said semiconductor substrate material and a tensile-strained second semiconductor material positioned on a surface of said first germanium-containing semiconductor material, wherein a concentration of germanium in said second semiconductor material is less than said first concentration of germanium; and performing a thermal anneal process to convert said first germanium-containing semiconductor material portion of said composite fin structure into a germanium-containing oxide isolation region positioned under said second semiconductor material of said composite fin structure, wherein said second semiconductor material is a tensile-strained final fin for an NMOS FinFET device.