A method for manufacturing a semiconductor structure includes preparing a dielectric structure formed with trenches respectively defined by lateral surfaces of the dielectric structure, forming spacer layers on the lateral surfaces, filling an electrically conductive material into the trenches to form electrically conductive features, selectively depositing a blocking layer on the dielectric structure, selectively depositing a dielectric material on the electrically conductive features to form a capping layer, removing the blocking layer and the dielectric structure to form recesses, forming sacrificial features in the recesses, forming a sustaining layer to cover the sacrificial features; and removing the sacrificial features to obtain the semiconductor structure formed with air gaps confined by the sustaining layer and the spacer layers.

A method for making a semiconductor structure, including: forming a conductive layer; forming a patterned mask layer on the conductive layer; patterning the conductive layer to form a recess and a conductive feature; forming a first dielectric layer over the patterned mask layer and filling the recess with the first dielectric layer; patterning the first dielectric layer to form an opening; selectively forming a blocking layer in the opening; forming an etch stop layer to cover the first dielectric layer and exposing the blocking layer; forming on the etch stop layer a second dielectric layer; forming a second dielectric layer on the etch stop layer; patterning the second dielectric layer to form a through hole and exposing the conductive feature; and filling the through hole with an electrically conductive material to form an interconnect electrically connected to the conductive feature.

A semiconductor structure includes a substrate, a dielectric layer, a first conductive feature and a second conductive feature. The substrate includes a semiconductor device. The dielectric layer is disposed on the substrate. The first conductive feature is formed in the first dielectric layer. The second conductive feature penetrates the first conductive feature and the dielectric layer, and is electrically connected to the first conductive feature and the semiconductor device.

A method for manufacturing a semiconductor structure includes forming a trench in a dielectric structure; forming a spacer layer on a lateral surface of the dielectric structure exposed by the trench; after forming the spacer layer, forming a first electrically conductive feature in the trench; removing at least portion of the dielectric structure to form a recess; forming an etch stop layer in the recess and over the first electrically conductive feature; and after forming the etch stop layer, depositing a dielectric layer in the recess and over the first electrically conductive feature.

A method for manufacturing a semiconductor device includes preparing an electrically conductive structure including a plurality of electrically conductive features, conformally forming a thermally conductive dielectric capping layer on the electrically conductive structure, conformally forming a dielectric coating layer on the thermally conductive dielectric capping layer, filling a sacrificial material into recesses among the electrically conductive features, recessing the sacrificial material to form sacrificial features in the recesses, forming a sustaining layer over the dielectric coating layer to cover the sacrificial features, and removing the sacrificial features to form air gaps covered by the sustaining layer. The thermally conductive dielectric capping layer has a thermal conductivity higher than that of the dielectric coating layer.

A method for manufacturing a semiconductor structure includes forming a plurality of dummy structures spaced apart from each other, forming a plurality of dielectric spacers laterally covering the dummy structures to form a plurality of trenches defined by the dielectric spacers, filling an conductive material into the trenches to form electrically conductive features, selectively depositing a capping material on the electrically conductive features to form a capping layer, removing the dummy structures to form a plurality of recesses defined by the dielectric spacers, filling a sacrificial material into the recesses so as to form sacrificial features, depositing a sustaining layer on the sacrificial features, and removing the sacrificial features to form air gaps confined by the sustaining layer and the dielectric spacers.

An integrated circuit device includes a dielectric structure within a metal interconnect over a substrate. The dielectric structure includes a cavity. A first dielectric layer provides a roof for the cavity. A second dielectric layer provides a floor for the cavity. A material distinct from the first dielectric layer and the second dielectric layer provides a side edge for the cavity. In a central area of the cavity, the cavity has a constant height. The height may be selected to provide a low parasitic capacitance between features above and below the cavity. The roof of the cavity may be flat. A gate dielectric may be formed over the roof. The dielectric structure is particularly useful for reducing parasitic capacitances when employing back-end-of-line (BEOL) transistors.

A method includes providing a semiconductor structure including a device fin protruding from a substrate, forming a dummy gate stack over the device fin, forming a first spacer over the device fin and the dummy gate stack, forming a second spacer over the first spacer, forming a dielectric feature adjacent to the second spacer, and replacing the dummy gate stack with a metal gate stack. Thereafter, the method removes the second spacer, thereby forming an air gap between the first spacer and the dielectric feature and wrapping around the device fin. The method then forms a sealing layer over the first spacer and the dielectric feature, thereby sealing the air gap.

A method includes forming a dummy gate over a substrate. A first gate spacer is formed on a side of the dummy gate. The dummy gate is replaced with a gate structure, such that that first gate spacer is on a side of the gate structure. The gate structure is etched back. After etching back the gate structure, a top portion of the first gate spacer is removed. A second gate spacer is formed over a remaining portion of the first gate spacer. After forming the second gate spacer, a dielectric cap is formed over the gate structure.

The present application discloses a method for fabricating a semiconductor device with a connection structure. The method includes providing a first semiconductor structure comprising a plurality of first conductive features adjacent to a top surface of the first semiconductor structure; forming a connection structure comprising a connection insulating layer on the top surface of the first semiconductor structure, a connection layer in the connection insulating layer, and a plurality of first porous interlayers on the plurality of first conductive features and in the connection insulating layer; and forming a second semiconductor structure comprising a plurality of second conductive features on the plurality of first porous interlayers.