US 9,793,379 B2 · FinFET spacer without substrate gouging or spacer foot

Abstract

The present invention relates generally to semiconductor devices, and more particularly, to a structure and method of forming a spacer adjacent to a gate in a fin field effect transistor (FinFET) device without resulting in substrate gouging or a spacer foot. A conformal spacer layer may be formed around a plurality of fins and a gate, wherein the conformal spacer layer may have a thickness above the plurality of fins that is at least one-half the distance between the individual fins. An isotropic etch may be used to remove excess spacer material around the plurality of fins (but not between the fins) and around the gate. An anisotropic etch may be used to remove the remaining spacer material from between the fins and around the gate, leaving a spacer adjacent to the gate without gouging the substrate surface between the fins.

Claims15

Dependent claims

A method of reducing substrate gouging between fins of a fin field effect transistor (finFET) during fabrication comprising:

forming a spacer layer on an upper surface of a substrate and around a gate and the fins, wherein the spacer layer has a thickness above an upper surface of the fins that is at least one-half of a distance between the fins, wherein forming the spacer layer is performed using liquid source misted chemical deposition;
and
removing a portion of the spacer layer using a timed reactive ion etch anisotropic etch, wherein a portion of the spacer layer remains on sidewalls of the gate as a gate spacer, and wherein the upper surface of the substrate between the fins remains substantially flush with a bottom surface of the fins, and wherein a substrate groove is formed in a portion of the upper surface of the substrate adjacent to, and outside of the fins, and wherein the substrate groove abuts the spacer layer.

Dependencies are inferred from the claim text.

FinFET spacer without substrate gouging or spacer foot

Life of this patent

FinFET spacer without substrate gouging or spacer foot

Life of this patent

Abstract

Claims15