The present disclosure provides a semiconductor device and a fabrication method thereof. The semiconductor device includes a substrate, a channel layer disposed on the substrate, and a barrier layer disposed on the channel layer. The semiconductor device further includes a dielectric layer disposed on the barrier layer and defining a first recess exposing a portion of the barrier layer. The semiconductor device further includes a first spacer disposed within the first recess, wherein the first spacer comprises a surface laterally connecting the dielectric layer to the barrier layer.

A tunneling field effect transistor according to an embodiment of the present invention includes: a first semiconductor layer having a first conductive type; a second semiconductor layer having a second conductive type and realizing a heterojunction with respect to the first semiconductor layer in a first region; a gate insulating layer over the second semiconductor layer in the first region; a gate electrode layer over the gate insulating layer; a first electrode layer electrically connected to the first semiconductor layer; a second electrode layer electrically connected to the second semiconductor layer; and a first insulating layer interposed between the first semiconductor layer and the second semiconductor layer in a second region adjacent to the first region toward the second electrode layer.

Example embodiments relate to a graphene device, methods of manufacturing and operating the same, and an electronic apparatus including the graphene device. The graphene device is a multifunctional device. The graphene device may include a graphene layer and a functional material layer. The graphene device may have a function of at least one of a memory device, a piezoelectric device, and an optoelectronic device within the structure of a switching device/electronic device. The functional material layer may include at least one of a resistance change material, a phase change material, a ferroelectric material, a multiferroic material, multistable molecules, a piezoelectric material, a light emission material, and a photoactive material.

A neuromorphic synaptic device based on a charge trap and having linearity and symmetricity improved by using a schottky junction and a neuromorphic system using the same are provided. The neuromorphic synaptic device includes a body layer formed on a semiconductor substrate, a source and a drain formed at a left side and a right side, or an upper side and a lower side of the body layer, a contact metal to form a schottky junction by making contact with the source and the drain, a gate insulating layer formed on the body layer, and including an oxide layer and a charge storage layer, and a gate formed on the gate insulating layer.

A semiconductor device includes at least one active pattern on a substrate, at least one gate electrode intersecting the at least one active pattern, source/drain regions on the at least one active pattern, the source/drain regions being on opposite sides of the at least one gate electrode, and a barrier layer between at least one of the source/drain regions and the at least one active pattern, the barrier layer being at least on bottoms of the source/drain regions and including oxygen.

An electrical contact structure (an MIS contact) includes one or more conductors (M-Layer), a semiconductor (S-Layer), and an interfacial dielectric layer (I-Layer) of less than 4 nm thickness disposed between and in contact with both the M-Layer and the S-Layer. The I-Layer is an oxide of a metal or a semiconductor. The conductor of the M-Layer that is adjacent to and in direct contact with the I-Layer is a metal oxide that is electrically conductive, chemically stable and unreactive at its interface with the I-Layer at temperatures up to 450° C. The electrical contact structure has a specific contact resistivity of less than or equal to approximately 10.sup.−5-10.sup.−7 Ω-cm.sup.2 when the doping in the semiconductor adjacent the MIS contact is greater than approximately 2×10.sup.19 cm.sup.−3 and less than approximately 10.sup.−8 Ω-cm.sup.2 when the doping in the semiconductor adjacent the MIS contact is greater than approximately 10.sup.20 cm.sup.−3.

The present disclosure relates to a method for fabricating a field-effect transistor structure on a substrate. The method includes forming a first semiconductor structure on the substrate, forming above the first semiconductor structure a gate structure that comprises a spacer layer laterally terminating the gate structure and has a lower etch rate than the first semiconductor structure with respect to a predetermined etchant, forming an undercut below the spacer layer by recessing the first semiconductor structure using the etchant, the undercut extending laterally below the spacer layer by not more than the thickness of the spacer layer, forming on the first semiconductor structure a second semiconductor structure filling the undercut, and forming a third semiconductor structure above the first semiconductor structure, wherein one of the second and third semiconductor structures forms the source of the field-effect transistor structure and the other one forms the drain.

A semiconductor device includes a barrier layer, a dielectric layer, a first spacer, a second spacer, and a gate. The dielectric layer is disposed on the barrier layer and defines a first recess. The first spacer is disposed on the barrier layer and within the first recess. The second spacer is disposed on the barrier layer and within the first recess. The first and second spacers are spaced apart from each other by a top surface of a portion of the barrier layer. The top surface of the portion of the barrier layer is recessed. The gate is disposed on the barrier layer, the dielectric layer, and the first and second spacers, in which the gate has a bottom portion located between the first and second spacers and making contact with the top surface of the portion of the barrier layer.

A semiconductor device includes a barrier layer, a dielectric layer, a first protection layer, a first spacer, and a gate. The dielectric layer is disposed on the barrier layer. The first protection layer is disposed on the barrier layer, in which the first protection layer extends from a first sidewall of the dielectric layer to a top surface of the barrier layer. The first spacer is disposed on and received by the first protection layer, in which a top end of the first protection layer comprises a first curved surface between the first spacer and the dielectric layer. The gate is disposed on the barrier layer, the dielectric layer, and the first spacer. The gate extends from a top surface of the dielectric layer and at least along the first curved surface of the first protection layer to make contact with the top surface of the barrier layer.

A semiconductor device includes at least one active pattern on a substrate, at least one gate electrode intersecting the at least one active pattern, source/drain regions on the at least one active pattern, the source/drain regions being on opposite sides of the at least one gate electrode, and a barrier layer between at least one of the source/drain regions and the at least one active pattern, the barrier layer being at least on bottoms of the source/drain regions and including oxygen.