Patent ID: 11916147
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 10:
11. A semiconductor device comprising:
a substrate;
a transistor over the substrate, wherein the transistor comprises a gate structure and source/drain regions on opposing sides of the gate structure;
a first dielectric layer over the substrate and around the transistor;
a contact plug extending through the first dielectric layer and electrically coupled to an underlying conductive feature, wherein the contact plug comprises:
an conductive material;
a first dielectric material around the conductive material; and
an air gap between the first dielectric material and first the dielectric layer, wherein an upper portion of the first dielectric layer distal from the substrate has a protrusion portion, wherein the protrusion portion extends into the air gap and separates the air gap into a lower air gap below the protrusion portion and an upper air gap over the protrusion portion; and

a second dielectric layer over the contact plug and the first dielectric layer, wherein the upper air gap is between the second dielectric layer and the protrusion portion.