A method of forming a comb-shaped transistor device is provided. The method includes forming a stack of alternating sacrificial spacer segments and channel segments on a substrate. The method further includes forming channel sidewalls on opposite sides of the stack of alternating sacrificial spacer segments and channel segments, and dividing the stack of alternating sacrificial spacer segments and channel segments into alternating sacrificial spacer slabs and channel slabs, wherein the channel slabs and channel sidewalls form a pair of comb-like structures. The method further includes trimming the sacrificial spacer slabs and channel slabs to form a nanosheet column of sacrificial plates and channel plates, and forming source/drains on opposite sides of the sacrificial plates and channel plates.

A network device includes one or more circuit components. The one or more circuit components include a semiconductor substrate, a first device terminal and a second device terminal, a drift region, and a mobility modulator. Both device terminals are coupled to the semiconductor substrate, the second device terminal being spatially separated from the first device terminal. The drift region is disposed on the semiconductor substrate between the first device terminal and the second device terminal, the drift region being configured to allow a flow of charge-carriers between the first device terminal and the second device terminal. The mobility modulator is coupled to the drift region, the mobility modulator being configured to selectively apply a field across the drift region responsive to one or more modulation signals, so as to modulate a mobility of charge-carriers as a function of longitudinal position along the drift region.

A device includes a semiconductor substrate. A gate stack on the semiconductor substrate includes a gate dielectric layer and a gate conductor layer. Low-k spacers are adjacent to the gate dielectric layer. Raised source/drain (RSD) regions are adjacent to the low-k spacers. The low-k spacers are embedded in an ILD on the RSD regions.

A semiconductor device has gate-all-around devices formed in respective regions on a substrate. The gate-all-around devices have nanowires at different levels. The threshold voltage of a gate-all-around device in first region is based on a thickness of an active layer in an adjacent second region. The active layer in the second region may be at substantially a same level as the nanowire in the first region. Thus, the nanowire in the first region may have a thickness based on the thickness of the active layer in the second region, or the thicknesses may be different. When more than one active layer is included, nanowires in different ones of the regions may be disposed at different heights and/or may have different thicknesses.

An embodiment includes a heterojunction tunneling field effect transistor including a source, a channel, and a drain; wherein (a) the channel includes a major axis, corresponding to channel length, and a minor axis that corresponds to channel width and is orthogonal to the major axis; (b) the channel length is less than 10 nm long; (c) the source is doped with a first polarity and has a first conduction band; (d) the drain is doped with a second polarity, which is opposite the first polarity, and the drain has a second conduction band with higher energy than the first conduction band. Other embodiments are described herein.

A semiconductor device includes a drain, a source, a gate electrode, and a nanowire between the source and drain. The nanowire has a first section with a first thickness and a second section with a second thickness greater than the first thickness. The second section is between the first section and at least one of the source or drain. The first nanowire includes a channel when a voltage is applied to the gate electrode.

Gate-all-around integrated circuit structures having oxide sub-fins, and methods of fabricating gate-all-around integrated circuit structures having oxide sub-fins, are described. For example, an integrated circuit structure includes an oxide sub-fin structure having a top and sidewalls. An oxidation catalyst layer is on the top and sidewalls of the oxide sub-fin structure. A vertical arrangement of nanowires is above the oxide sub-fin structure. A gate stack is surrounding the vertical arrangement of nanowires and on at least the portion of the oxidation catalyst layer on the top of the oxide sub-fin structure.

A semiconductor structure and fabrication method is provided for gate all around (GAA) nanosheet devices. The semiconductor structure comprises a substrate, a gate stack on the substrate with a plurality of gate regions and silicon-based channel regions alternatingly arranged one on the other. A length of the gate regions is smaller than a length of the channel regions. Thus, pockets are formed on a side of the gate stack, each pocket being arranged next to one gate region and between the two channel regions adjacent to the gate region. Further, a silicon-based first contact region extends in a distance to the side of the gate stack, and a silicon-based filler material is arranged between the first contact region and the first side of the gate stack and in each first pocket.

A method for producing a device comprising GAA transistors. Advantageously, the channels of the transistors are produced by deposition of a semiconductor material, preferably a 2D material, after successive removal of certain layers of the initial stack. The gates-all-around are produced after selective removal of the other layers from the initial stack. The initial stack does not comprise the semiconductor material, nor the material of the gates. The subsequent deposition of the semiconductor material aims to better preserve the semiconductor material.

A method for fabricating a GAA nanosheet structure, comprising: forming at least two channel layers and at least one sacrificial layer alternately stacked on a substrate to form a channel stack; forming, on the substrate, a dummy gate astride the channel stack; forming a first sidewall on a surface of the dummy gate; etching the sacrificial layer to form a recess at a side surface of the channel stack; forming a second sidewall within the recess; forming a source and a drain at two sides of the channel stack; in response to a channel layer being in contact with the dummy gate, etching the dummy gate and the channel layer to expose the at least one sacrificial layer, and then etching the at least one sacrificial layer to form a space for manufacturing a surrounding gate; and forming a metallic surrounding gate in the space.