Supportive layer in source/drains of FinFET devices
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsJung-Chi Tai, Chii-Horng Li, Pei-Ren Jeng, Yen-Ru Lee, Yan-Ting Lin, Chih-Yun Chin
Life of this patent
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Abstract
An embodiment is a semiconductor structure. The semiconductor structure includes a fin on a substrate. A gate structure is over the fin. A source/drain is in the fin proximate the gate structure. The source/drain includes a bottom layer, a supportive layer over the bottom layer, and a top layer over the supportive layer. The supportive layer has a different property than the bottom layer and the top layer, such as a different material, a different natural lattice constant, a different dopant concentration, and/or a different alloy percent content.
Claims20
A semiconductor structure comprising:
- a fin on a substrate;
- a gate structure over the fin;
- a source/drain in the fin proximate the gate structure, the source/drain comprising:
- a bottom layer, wherein the bottom layer comprises p-doped silicon germanium;
- a supportive layer over the bottom layer;
- a top layer over the supportive layer, the top layer comprising p-doped silicon germanium, wherein the supportive layer has a different property than the bottom layer and the top layer, the different property selected from a group consisting of a different material, a different natural lattice constant, a different dopant concentration, and a different alloy percent content;
- and
- a capping layer over the top layer;
- and
- a contact extending partially through the source/drain, wherein a bottom surface of the contact and a top surface of the top layer are in direct contact.
A semiconductor structure comprising:
- a substrate;
- a first fin and a second fin on the substrate;
- a gate structure over the first fin and the second fin;
- and
- source/drains on opposing sides of the gate structure, each of the source/drains comprising:
- a first bottom layer in the first fin;
- a second bottom layer in the second fin, the first bottom layer and the second bottom layer are physically separate, the first bottom layer and the second bottom layer are disposed in a plane parallel to a major surface of the substrate;
- a plurality of supportive layers over the first bottom layer and the second bottom layer;
- one or more intermediate layers between the plurality of supportive layers;
- and
- a top layer over the plurality of supportive layers, wherein the plurality of supportive layers comprises silicon germanium with an atomic percent content of germanium less than the first and second bottom layers, less than the one or more intermediate layers, and less than the top layer.
A semiconductor structure comprising:
- a fin on a substrate;
- a gate structure over the fin;
- a source/drain in the fin proximate the gate structure, the source/drain comprising:
- a bottom layer comprising p-doped silicon germanium having a first germanium atomic percent content;
- a supportive layer over the bottom layer;
- a top layer over the supportive layer, the top layer comprising p-doped silicon germanium having a second germanium atomic percent content greater than the first germanium atomic percent content, wherein the supportive layer comprises silicon germanium having a third germanium atomic percent content less than the first germanium atomic percent content of the bottom layer and less than the second germanium atomic percent content of the top layer;
- and
- a capping layer over the top layer;
- and
- a contact extending partially through the source/drain, wherein a bottom surface of the contact and a top surface of the top layer and are in direct physical contact.
Dependencies are inferred from the claim text.