A semiconductor device including an active pattern on a substrate and extending lengthwise in a first direction parallel to an upper surface of the substrate; a gate structure on the active pattern, the gate structure extending in a second direction parallel to the upper surface of the substrate and crossing the first direction; channels spaced apart from each other along a third direction perpendicular to the upper surface of the substrate, each of the channels extending through the gate structure along the first direction; a source/drain layer on a portion of the active pattern adjacent to the gate structure in the first direction, the source/drain layer contacting the channels; inner spacers between the gate structure and the source/drain layer, the inner spacers contacting the source/drain layer; and channel connection portions between each of the inner spacers and the gate structure, the channel connection portions connecting the channels with each other.

The present disclosure provides a semiconductor device and a fabrication method thereof. The semiconductor device includes a first III-nitride layer, a second III-nitride layer, a first contact layer, a second contact layer, a structure, and a gate layer. The second III-nitride layer is in direct contact with the first III-nitride layer. The first contact layer and the second contact layer are disposed over the second III-nitride layer. The structure is adjacent to an interface of the first III-nitride layer and the second III-nitride layer, and a material of the structure is different from a material of the first III-nitride layer or a material of the second III-nitride layer. The gate layer is disposed between the first contact layer and the second contact layer.

A method includes providing a semiconductor body including a plurality of two-dimensional charge carrier gas channels, forming a gate fin by forming a pair of gate trenches in an upper surface of the semiconductor body, the pair of gate trenches exposing each one of two-dimensional charge carrier gas channels, providing source and drain contacts that are electrically connected to each one of the plurality of two-dimensional charge carrier gas channels, providing a gate structure that is configured to control a conductive connection between the source and drain contacts, wherein providing the gate structure includes forming a layer of doped type III-nitride semiconductor material that covers the gate fin and extends into the gate trenches, and forming a conductive gate electrode on top of the layer of doped type III-nitride semiconductor material.

A semiconductor structure including a first logic cell having a first plurality of nanosheet devices along an axis and a second logic cell having a second plurality of nanosheet devices along the axis. Nanosheets of the second plurality of nanosheet devices are wider than nanosheets of the first plurality of nanosheet devices. The first logic cell is a same type as the second logic cell. The first and second logic cells can include inverter circuits or NAND circuits or NOR circuits. When the first logic cell has a height X, a width Y, and an effective width (W.sub.eff) Z, then the second logic cell has a height 2X, a width Y, and W.sub.eff>2.5 Z.

In some examples, a transistor comprises a gallium nitride (GaN) layer; a GaN-based alloy layer having a top side and disposed on the GaN layer, wherein source, drain, and gate contact structures are supported by the GaN layer; and a first doped region positioned in a drain access region and extending from the top side into the GaN layer.

A semiconductor device formed by forming a stack of alternating horizontal nanosheet layers, recessing the stack for an n-type field effect transistor (nFET), growing crystalline semiconductor adjacent to the stack, forming vertical nanosheets from the crystalline semiconductor, forming inner spacers between the vertical nanosheets, and forming a high-k metal gate structure around the horizontal nanosheets and the vertical nanosheets.

A semiconductor device including an active pattern on a substrate and extending lengthwise in a first direction parallel to an upper surface of the substrate; a gate structure on the active pattern, the gate structure extending in a second direction parallel to the upper surface of the substrate and crossing the first direction; channels spaced apart from each other along a third direction perpendicular to the upper surface of the substrate, each of the channels extending through the gate structure along the first direction; a source/drain layer on a portion of the active pattern adjacent to the gate structure in the first direction, the source/drain layer contacting the channels; inner spacers between the gate structure and the source/drain layer, the inner spacers contacting the source/drain layer; and channel connection portions between each of the inner spacers and the gate structure, the channel connection portions connecting the channels with each other.

A semiconductor device includes an underlayer made of a first nitride semiconductor, a first buffer layer made of a second nitride semiconductor, provided on the underlayer, and subjected to compressive stress from the underlayer in an in-plane direction which is perpendicular to a thickness direction of the underlayer, a second buffer layer made of a third nitride semiconductor, provided on the first buffer layer, and subjected to compressive stress from the first buffer layer in the in-plane direction, a channel layer made of a fourth nitride semiconductor, provided on the second buffer layer, and subjected to compressive stress from the second buffer layer in the in-plane direction, and a barrier layer made of a fifth nitride semiconductor, and provided above the channel layer.

A semiconductor device includes a first field-effect transistor positioned over a substrate, a second field-effect transistor stacked over the first field-effect transistor, a third field-effect transistor stacked over the second field-effect transistor, and a fourth field-effect transistor stacked over the third field-effect transistor. A bottom gate structure is disposed around a first channel structure of the first field-effect transistor and positioned over the substrate. An intermediate gate structure is disposed over the bottom gate structure and around a second channel structure of the second field-effect transistor and a third channel structure of the third field-effect transistor. A top gate structure is disposed over the intermediate gate structure and around a fourth channel structure of the fourth field-effect transistor. An inter-level contact is formed to bypass the intermediate gate structure from a first side of the intermediate gate structure, and arranged between the bottom gate structure and the top gate structure.

A method of manufacturing a semiconductor device is provided. The method includes forming a channel layer and an active layer over a substrate; forming a doped epitaxial layer over the active layer; patterning the doped epitaxial layer, the active layer, and the channel layer to form a fin structure comprising a doped epitaxial fin portion, an active fin portion below the doped epitaxial fin portion, and a channel fin portion below the active fin portion; removing the doped epitaxial fin portion; and forming a gate electrode at least partially extending along a sidewall of the fin structure to form a Schottky barrier between the gate electrode and the fin structure after removing the doped epitaxial fin portion.