Tuning Strain in Semiconductor Devices

摘要

A Fin Field-Effect Transistor (FinFET) includes a semiconductor layer over a substrate, wherein the semiconductor layer forms a channel of the FinFET. A first silicon germanium oxide layer is over the substrate, wherein the first silicon germanium oxide layer has a first germanium percentage. A second silicon germanium oxide layer is over the first silicon germanium oxide layer. The second silicon germanium oxide layer has a second germanium percentage greater than the first germanium percentage. A gate dielectric is on sidewalls and a top surface of the semiconductor layer. A gate electrode is over the gate dielectric.

主权项

1. A device comprising:
a semiconductor substrate; isolation regions extending into the semiconductor substrate; and a Fin Field-Effect Transistor (FinFET) comprising:
a semiconductor layer over the semiconductor substrate, wherein the semiconductor layer forms a channel of the FinFET, and the semiconductor layer is higher than top surfaces of the isolation regions;a silicon germanium oxide layer over the semiconductor substrate and under the semiconductor layer, wherein a portion of the silicon germanium oxide layer extends between opposite portions of the isolation regions, and extends below top surfaces of the isolation regions;a gate dielectric on sidewalls and a top surface of the semiconductor layer; anda gate electrode over the gate dielectric.