Raised Epitaxial LDD in MuGFETs and Methods for Forming the Same

摘要

Embodiments include Multiple Gate Field-Effect Transistors (MuGFETs) and methods of forming them. In an embodiment, a structure includes a substrate, a fin, masking dielectric layer portions, and a raised epitaxial lightly doped source/drain (LDD) region. The substrate includes the fin. The masking dielectric layer portions are along sidewalls of the fin. An upper portion of the fin protrudes from the masking dielectric layer portions. A first spacer is along a sidewall of a gate structure over a channel region of the fin. A second spacer is along the first spacer. The raised epitaxial LDD region is on the upper portion of the fin, and the raised epitaxial LDD region adjoins a sidewall of the first spacer and is disposed under the second spacer. The raised epitaxial LDD region extends from the upper portion of the fin in at least two laterally opposed directions and a vertical direction.

主权项

1. A structure comprising:
a substrate comprising a fin and isolation regions adjoining the fin; a masking dielectric layer portions along sidewalls of the fin and extending from the isolation regions, an upper portion of the fin protruding from the masking dielectric layer portions; a gate structure over a channel region of the fin; a first spacer along a sidewall of the gate structure; a second spacer along the first spacer, the first spacer being disposed between the second spacer and the gate structure; a raised epitaxial lightly doped source/drain (LDD) region on the upper portion of the fin, the raised epitaxial LDD region adjoining a sidewall of the first spacer and being disposed under the second spacer, the raised epitaxial LDD region extending from the upper portion of the fin in at least two laterally opposed directions and a vertical direction; and a source/drain region in the fin.