US 12,406,877 B2Granted

Homogeneous source/drain contact structure

AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.

InventorsYa-Ching Tseng, Chang-Wen Chen, Po-Hsiang Huang

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Abstract

A method according to the present disclosure includes receiving a workpiece that includes a first source/drain feature, a first dielectric layer over the first source/drain feature, and a source/drain contact disposed in the first dielectric layer and over the first source/drain feature. The method further includes depositing a second dielectric layer over the source/drain contact and the first dielectric layer, forming a source/drain contact via opening through the second dielectric layer to expose the source/drain contact, depositing a sacrificial plug in the source/drain contact via opening, depositing a third dielectric layer over the second dielectric layer and the sacrificial plug, forming a trench in the third dielectric layer to expose the sacrificial plug, removing the sacrificial plug to expose the source/drain contact via opening, and after the removing of the sacrificial plug, forming an integrated conductive feature into the trench and the exposed source/drain contact via opening.

Claims20

Dependent claims

A method, comprising:

receiving a workpiece comprising:
a first gate structure and a second gate structure,
a first gate spacer disposed along a sidewall of the first gate structure,
a second gate spacer disposed along a sidewall of the second gate structure,
a first source/drain feature and a second source/drain feature disposed between the first gate structure and the second gate structure along a first direction,
a contact etch stop layer (CESL) over the first source/drain feature,
a first dielectric layer over the CESL and disposed between the first gate spacer and the second gate spacer such that the first dielectric layer is spaced apart from the first gate spacer and the second gate spacer by the CESL,
a first etch stop layer (ESL) over and in contact with the CESL and the first dielectric layer,
a middle dielectric layer over the first ESL, and
a source/drain contact extending through the middle dielectric layer, the first ESL, the first dielectric layer, and the CESL to interface the first source/drain feature;
depositing a second ESL over the source/drain contact and the first dielectric layer;
depositing a second dielectric layer over the second ESL;
forming a source/drain contact via opening by etching through the second dielectric layer and the second ESL to expose the source/drain contact, wherein the etching forms an undercut below the second ESL;
depositing a sacrificial plug in the source/drain contact via opening such that a portion of the sacrificial plug fills in the undercut;
depositing a third dielectric layer over the second dielectric layer and the sacrificial plug;
forming a trench in the third dielectric layer to expose the sacrificial plug;
removing the sacrificial plug to expose the source/drain contact via opening;
and
after the removing of the sacrificial plug, forming an integrated conductive feature into the trench and the exposed source/drain contact via opening,
wherein the first source/drain feature and the second source/drain feature are aligned along a second direction perpendicular to the first direction,
wherein the trench spans over a top surface of the second source/drain feature.

18 more elements

A method, comprising:

receiving a workpiece comprising:
a first source/drain feature disposed over a first fin,
a second source/drain feature disposed over a second fin extending lengthwise in parallel with the first fin along a first direction,
a contact etch stop layer (CESL) over the first source/drain feature,
a first dielectric layer over the CESL,
a first etch stop layer (ESL) over the CESL and the first dielectric layer,
a middle dielectric layer over the first ESL, and
a source/drain contact extending through the middle dielectric layer, the first ESL, the first dielectric layer, and CESL to interface the first source/drain feature;
depositing a second etch stop layer (ESL) and a second dielectric layer over the source/drain contact and the first dielectric layer;
forming a source/drain contact via opening by etching through the second ESL and the second dielectric layer to expose the source/drain contact, wherein the etching forms an undercut below the second ESL;
depositing a sacrificial plug in the source/drain contact via opening such that a portion of the sacrificial plug fills in the undercut;
depositing a third ESL and a third dielectric layer over the second dielectric layer and the sacrificial plug;
forming a trench in the third ESL and the third dielectric layer to expose the sacrificial plug, wherein the trench spans over a top surface of the second source/drain feature;
selectively removing the sacrificial plug to expose the source/drain contact via opening;
and
after the removing of the sacrificial plug, forming a source/drain contact via in the source/drain contact via opening and a metal line in the trench.

13 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/388,171Filed 29 Jul 2021 · us provisional application
Priority: 15 Apr 2021
Published: US 2022/0336269 A120 Oct 2022
Granted: 2 Sep 2025
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

H10W 20/085
For dual-damascene structures: involving intermediate temporary filling with material
H10W 20/42
Characterised by their conductive parts: vias, e.g. via plugs
H10W 20/47
Characterised by their insulating parts: comprising two or more dielectric layers having different properties, e.g. different dielectric constants
H10W 20/083
By forming openings in the dielectric parts: the openings being via holes penetrating underlying conductors