The present disclosure provides a semiconductor structure. The semiconductor structure includes a substrate having an active region and an isolation region. The semiconductor structure includes gate stacks on the substrate that extend over the active region and the isolation region. The semiconductor structure includes a gate spacer on sidewalls of the gate stacks. The semiconductor structure includes an interlevel dielectric (ILD) layer over the substrate and implanted with one or more dopants, the ILD layer having a top implanted portion over a bottom nonimplanted portion. The top implanted portion seals an air gap between a sidewall of the ILD layer and the gate spacer.

The invention discloses a transistor structure including a substrate, a semiconductor layer disposed on the substrate and a gate layer disposed on the semiconductor layer, wherein the gate layer includes at least one gate having a first height, a first side and a second side opposite to the first side, a first dielectric spacer is disposed at the first side of the at least one gate, a first air spacer having a second height is disposed inside the first dielectric spacer, and the second height is lower than the first height.

The present application discloses a method for fabricating semiconductor device with a graphene-based element. The method includes providing a substrate; forming a stacked gate structure over the substrate; forming first spacers on sidewalls of the gate stack structure, wherein the first spacers comprise graphene; forming sacrificial spacers on sidewall of the first spacers; and forming second spacers on sidewall of the sacrificial spacers.

A semiconductor device includes a stacked structure including conductive layers and insulating layers stacked alternately with each other, a channel layer passing through the stacked structure, a ferroelectric layer surrounding a sidewall of the channel layer, a first dielectric layer surrounding a sidewall of the ferroelectric layer, and sacrificial patterns interposed between the first dielectric layer and the insulating layers and including a material with a higher dielectric constant than the first dielectric layer.

A method includes forming a gate stack over a semiconductor region, and forming a first gate spacer on a sidewall of the gate stack. The first gate spacer includes an inner sidewall spacer, and a dummy spacer portion on an outer side of the inner sidewall spacer. The method further includes removing the dummy spacer portion to form a trench, and forming a dielectric layer to seal a portion of the trench as an air gap. The air gap and the inner sidewall spacer in combination form a second gate spacer. A source/drain region is formed to have a portion on an outer side of the second gate spacer.

The present disclosure describes a method for forming gate spacer structures with air-gaps to reduce the parasitic capacitance between the transistor's gate structures and the source/drain contacts. In some embodiments, the method includes forming a gate structure on a substrate and a spacer stack on sidewall surfaces of the gate structure where the spacer stack comprises an inner spacer layer in contact with the gate structure, a sacrificial spacer layer on the inner spacer layer, and an outer spacer layer on the sacrificial spacer layer. The method further includes removing the sacrificial spacer layer to form an opening between the inner and outer spacer layers, depositing a polymer material on top surfaces of the inner and outer spacer layers, etching top sidewall surfaces of the inner and outer spacer layers to form a tapered top portion, and depositing a seal material.

The present disclosure describes a method for forming gate spacer structures with air-gaps to reduce the parasitic capacitance between the transistor's gate structures and the source/drain contacts. In some embodiments, the method includes forming a gate structure on a substrate and a spacer stack on sidewall surfaces of the gate structure—where the spacer stack comprises an inner spacer layer in contact with the gate structure, a sacrificial spacer layer on the inner spacer layer, and an outer spacer layer on the sacrificial spacer layer. The method further includes removing the sacrificial spacer layer to form an opening between the inner and outer spacer layers, depositing a polymer material on top surfaces of the inner and outer spacer layers, etching top sidewall surfaces of the inner and outer spacer layers to form a tapered top portion, and depositing a seal material.

A semiconductor device and a method of forming the same are provided. The method includes forming a sacrificial gate structure over an active region. A first spacer layer is formed along sidewalls and a top surface of the sacrificial gate structure. A first protection layer is formed over the first spacer layer. A second spacer layer is formed over the first protection layer. A third spacer layer is formed over the second spacer layer. The sacrificial gate structure is replaced with a replacement gate structure. The second spacer layer is removed to form an air gap between the first protection layer and the third spacer layer.

The present disclosure provides a method of fabricating a semiconductor structure in accordance with some embodiments. The method includes receiving a substrate having an active region and an isolation region; forming gate stacks on the substrate that extends from the active region to the isolation region; forming an inner gate spacer and an outer gate spacer on sidewalls of the gate stacks; forming an interlevel dielectric (ILD) layer on the substrate; forming a mask layer over the substrate that exposes a portion of the ILD layer and a portion of the outer gate spacer; selectively etching the exposed portion of the outer gate spacer, resulting in an air gap between the inner gate spacer and the ILD layer; and performing an ion implantation process on the exposed portion of the ILD layer to seal the air gap.

According to one embodiment, a semiconductor device includes first, and second conductive members, first, second, and third semiconductor regions, and an insulating part. A direction from the first conductive member toward the second conductive member is along a first direction. The first semiconductor region includes first and second partial regions. A second direction from the first partial region toward the second partial region crosses the first direction. The first conductive member is between the first partial region and the second conductive member. A direction from the second partial region toward the second semiconductor region is along the first direction. A direction from the second conductive member toward the second semiconductor region is along the second direction. The third semiconductor region is between the second partial region and the second semiconductor region. The insulating part includes a first insulating region, a second insulating region, and a third insulating region.