Transistors and methods of forming the same include forming a semiconductor fin from a first material on dielectric layer. Material is etched away from the dielectric layer directly underneath a channel region of the semiconductor fin, with the semiconductor fin still being supported by the dielectric layer in a source and drain region. A gate stack is formed around the channel region of the semiconductor fin, with a portion of the gate stack underneath the semiconductor fin being larger than a portion of the gate stack above the semiconductor fin.

One illustrative method disclosed includes, among other things, removing a portion of an initial gate cap layer and a portion of an initial sidewall spacer so as to thereby define a gate contact cavity that exposes a portion of a gate structure, completely forming a conductive gate contact structure (CB) in a gate contact cavity, wherein the entire conductive gate contact structure (CB) is positioned vertically above the active region. The method also comprises removing the remaining portion of the initial gate cap layer and to recess a vertical height of exposed portions of the initial sidewall spacer to thereby define a recessed sidewall spacer and a gate cap cavity and forming a replacement gate cap layer in the gate cap cavity so as to define an air space between an upper surface of the recessed sidewall spacer and a lower surface of the replacement gate cap layer.

A semiconductor device includes a semiconductor substrate, a gate dielectric layer, a gate electrode and source and drain regions. The gate dielectric layer extends into a first trench in the semiconductor substrate. The gate electrode is over the gate dielectric layer and is at least partially embedded in the first trench in the semiconductor substrate. The source and drain regions are in the semiconductor substrate and proximate the first trench in the semiconductor substrate.

A method includes forming a dummy gate stack, forming a dielectric layer, with the dummy gate stack located in the dielectric layer, removing the dummy gate stack to form a opening in the dielectric layer, forming a metal layer extending into the opening, and etching back the metal layer. The remaining portions of the metal layer in the opening have edges lower than a top surface of the dielectric layer. A conductive layer is selectively deposited in the opening. The conductive layer is over the metal layer, and the metal layer and the conductive layer in combination form a replacement gate.

A method for fabricating semiconductor device includes the steps of first forming a metal gate on a substrate and a spacer around the metal gate, in which the metal gate comprises a high-k dielectric layer, a work function metal layer, and a low-resistance metal layer. Next, part of the high-k dielectric layer is removed to form an air gap between the work function metal layer and the spacer.

A method of fabricating a FinFET device includes forming contact openings for source/drain contacts prior to performing a replacement metal gate (RMG) module. Etch selective metals are used to form source/drain contacts and gate contacts optionally within active device regions using a block and recess technique.

A thin-film transistor (TFT) array substrate including at least one TFT, the at least one TFT including a semiconductor layer including a source region and a drain region having a first doping concentration on a substrate, a channel region between the source and drain regions and having a second doping concentration, the second doping concentration being lower than the first doping concentration, and a non-doping region extending from the source and drain regions; a gate insulating layer on the semiconductor layer; a gate electrode on the gate insulating layer and at least partially overlapping the channel region; and a source electrode and a drain electrode insulated from the gate electrode and electrically connected to the source region and the drain region, respectively.

Transistors and methods of forming the same include forming a semiconductor fin from a first material on dielectric layer. Material is etched away from the dielectric layer directly underneath a channel region of the semiconductor fin, with the semiconductor fin still being supported by the dielectric layer in a source and drain region. A gate stack is formed around the channel region of the semiconductor fin, with a portion of the gate stack underneath the semiconductor fin being larger than a portion of the gate stack above the semiconductor fin.

A semiconductor device includes a substrate including an active region, a gate structure disposed in a gate trench in the substrate, a bit line disposed on the substrate and electrically connected to the active region on one side of the gate structure, and a capacitor disposed on the bit line and electrically connected to the active region on another side of the gate structure. The gate structure includes a gate dielectric layer disposed on bottom and inner side surfaces of the gate trench, a conductive layer disposed on the gate dielectric layer in a lower portion of the gate trench, sidewall insulating layers disposed on the gate dielectric layer, on an upper surface of the conductive layer, a graphene conductive layer disposed on the conductive layer, and a buried insulating layer disposed between the sidewall insulating layers on the graphene conductive layer.

A semiconductor component, which includes a substrate, an interfacial layer disposed on the substrate, a first metal gate structure and a second metal gate structure disposed on the substrate. The first metal gate structure includes a first high-k dielectric layer disposed on the interfacial layer, and a first metal gate layer disposed on the first high-k dielectric layer. The second metal gate structure includes a second high-k dielectric layer disposed on the interfacial layer, a third high-k dielectric layer disposed on the second high-k dielectric layer, and a second metal gate layer disposed on the third high-k dielectric layer.