US 9,437,499 B2 · Semiconductor device including merged-unmerged work function metal and variable fin pitch

Abstract

A method of varying a threshold voltage of a semiconductor device includes forming plural first semiconductor fins atop a substrate and which are separated from one another according to a first fin pitch to define first fin trenches having a first width. At least one second semiconductor fin is formed atop the substrate and is separated from the plural first semiconductor fins by a second fin pitch to define second fin trenches having a second width. The method further includes forming a work function metal layer in the first and second fin trenches. The second trenches have a first cavity formed therein such that at least one second semiconductor fin has a different concentration of work function metal layer with respect to the first plural semiconductor fins so as to vary the threshold voltage of the at least one second semiconductor fin with respect to the first plural semiconductor fins.

Claims20

Dependent claims

A method of varying a threshold voltage of a semiconductor device, the method comprising:

forming plural first semiconductor fins atop a substrate, the plural first semiconductor fins separated from one another according to a first fin pitch to define first fin trenches having a first width;
forming at least one second semiconductor fin separated from the plural first semiconductor fins by a second fin pitch to define second fin trenches having a second width;
and
forming at least one work function metal layer in the first and second fin trenches, wherein the second trenches have a first cavity formed therein such that at least one second semiconductor fin has a different concentration of work function metal layer with respect to the first plural semiconductor fins so as to vary the threshold voltage of the at least one second semiconductor fin with respect to the first plural semiconductor fins.

1 more element

A method of tuning a threshold voltage of a semiconductor device, the method comprising:

forming a plurality of semiconductor fins on an upper surface of a substrate, the semiconductor fins including at least one isolated semiconductor fin having a first fin pitch (dif) that is different from a second fin pitch (df) of the remaining semiconductor fins,
wherein a first trench separates the at least one isolated semiconductor fin from the remaining semiconductor fins, and second trenches separate the remaining semiconductor fins from one another, the second trenches sized differently from the first trench;
and
depositing at least one work function metal (WFM) layer in the first trench and the second trenches so as to cover the at least one isolated semiconductor fin and the remaining semiconductor fins,
wherein a threshold voltage differential of the at least one isolated semiconductor fin and the remaining semiconductor fins is tuned based on a thickness of the at least one WFM layer.

2 more elements

Dependencies are inferred from the claim text.

Semiconductor device including merged-unmerged work function metal and variable fin pitch

Life of this patent

Semiconductor device including merged-unmerged work function metal and variable fin pitch

Life of this patent

Abstract

Claims20