US 2017/0365706 A1 · FIELD EFFECT TRANSISTORS WITH SELF-ALIGNED EXTENSION PORTIONS OF EPITAXIAL ACTIVE REGIONS

Abstract

A gate structure is formed across a single crystalline semiconductor fin. An amorphizing ion implantation is performed employing the gate structure as an implantation mask to amorphize surface portions of the semiconductor fin into inverted U-shaped amorphous semiconductor portions. A gate spacer is formed around the gate structure, and the inverted U-shaped amorphous semiconductor portions are etched selective to a single crystalline portion of the semiconductor fin and the gate structure. A pair of inverted U-shaped cavities is formed underneath the gate spacer and above the remaining portion of the semiconductor fin. A doped epitaxial semiconductor material is deposited by a selective epitaxy process to form doped epitaxial active regions that include self-aligned extension portions underlying the gate spacer.

Claims19

Dependent claims

A semiconductor structure comprising:

a semiconductor fin located on a substrate and including a first portion having a first height throughout and a pair of second portions, each of said pair of second portions having a second height throughout and adjoined to said first portion;
a gate structure including a gate dielectric and a gate electrode and contacting a top surface and sidewall surfaces of said first portion;
a gate spacer laterally surrounding said gate structure, wherein a bottom surface of said gate spacer is planar with a horizontal interface between said gate structure and said first portion;
and
an active region including a doped epitaxial semiconductor material and contacting a top surface of one of said second portions, said bottom surface of said gate spacer, and an outer sidewall of said gate spacer.

2 more elements

Dependencies are inferred from the claim text.

Field effect transistors with self-aligned extension portions of epitaxial active regions

Life of this patent

Field effect transistors with self-aligned extension portions of epitaxial active regions

Life of this patent

Abstract

Claims19