The present disclosure provides a quantum well fin field effect transistor (QWFinFET). The QWFinFET includes a semiconductor fin over a substrate and a combo quantum well (QW) structure over the semiconductor fin. The combo QW structure includes a QW structure over a top portion of the semiconductor fin and a middle portion of the semiconductor fin. The semiconductor fin and the QW comprise different semiconductor materials. The QWFinFET also includes a gate stack over the combo QW structure.

A FinFET device structure and method for forming the same is provided. The FinFET device structure includes an oxide layer formed over a substrate and a fin structure formed over the oxide layer. The fin structure is made of a semiconductor layer, and the semiconductor layer includes a first portion, a second portion and a third portion. The second portion is between the first portion and the third portion. The first portion, the second portion and the third portion construct a U-shaped trench, and the second portion is below the U-shaped trench. The FinFET device structure further includes a gate structure formed in the U-shaped trench.

According to one embodiment, a field-effect transistor includes a source region of a first conductivity type, a drain region of the first conductivity type and a channel region of the first conductivity type between the source region and the drain region, the source region, the drain region and the channel region being disposed in a polycrystalline semiconductor layer; a first layer including an amorphous semiconductor layer disposed on the channel region; a gate insulating layer disposed on the first layer; and a gate electrode disposed on the gate insulating layer.

A FinFET device structure and method for forming the same is provided. The FinFET device structure includes an oxide layer formed over a substrate and a fin structure formed over the oxide layer. The fin structure is made of a semiconductor layer, and the semiconductor layer includes a first portion, a second portion and a third portion. The second portion is between the first portion and the third portion. The first portion, the second portion and the third portion construct a U-shaped trench, and the second portion is below the U-shaped trench. The FinFET device structure further includes a gate structure formed in the U-shaped trench.

A semiconductor device includes a semiconductor substrate, an element isolation film, and a fin having side surfaces facing each other in a first direction of an upper surface and a main surface connecting the facing side surfaces and extending in a second direction orthogonal to the first direction. The device further includes a control gate electrode arranged over the side surface via a gate insulation film and extending in the first direction, and a memory gate electrode arranged over the side surface via another gate insulation film having a charge accumulation layer and extending in the first direction. Furthermore, an overlap length by which the memory gate electrode overlaps with the side surface is smaller than an overlap length by which the control gate electrode overlaps with the side surface in the direction orthogonal to the upper surface.

A method for fabricating a semiconductor device comprises forming a fin in a layer of III-V compound semiconductor material on a silicon-on-insulator substrate; forming a semiconductor extension on the fin, the semiconductor extension comprising a III-V compound semiconductor material that is different from a material forming the fin in the III-V compound semiconductor layer; forming a dummy gate structure and a spacer across and perpendicular to the fin; forming a source/drain layer on a top surface of the substrate adjacent to the dummy gate structure; planarizing the source/drain layer; removing the dummy gate structure to expose a portion of the semiconductor extension on the fin; removing the exposed portion of the semiconductor extension; etching the semiconductor extension to undercut the spacer; and forming a replacement gate structure in place of the removed dummy gate structure and removed exposed portion of the semiconductor extension.

A fin-type field effect transistor includes a semiconductor body formed on a substrate, the semiconductor body having a top surface and a pair of laterally opposite sidewalls, and a gate electrode formed above the sidewalls and the top surface of the semiconductor body. The semiconductor body further includes a source region formed on an end portion of the semiconductor body, a drain region formed on another end portion of the semiconductor body, and a channel region formed between the source region and the drain region and surrounded by the gate electrode, wherein a doping concentration of the channel region decreases with increasing distance from the top surface and the sidewalls.

Methods for fabricating transistor structures are provided, the methods including: forming a fin structure with an upper fin portion and a lower fin portion, the upper fin portion including a sacrificial material; forming a gate structure over the fin; selectively removing the upper fin portion to form a tunnel between the gate structure and lower fin portion; and providing a channel material in the tunnel to define the channel region of the gate structure. The sacrificial material may be a material that can be selectively etched without etching the material of the lower fin portion. The channel material may further be provided to form source and drain regions of the transistor structure, which may result in a junctionless FinFET structure.

A method for producing a 3D semiconductor device including: providing a first level, including a single crystal layer; forming memory control circuits in and/or on the first level which include first single crystal transistors and at least two interconnection metal layers; forming at least one second level; performing a first etch step into the second level; forming at least one third level on top of the second level; performing additional processing steps to form first memory cells within the second level and second memory cells within the third level, where each of the first memory cells include at least one second transistor including a metal gate, where each of the second memory cells include at least one third transistor; and performing bonding of the first level to the second level, where the first level includes control of power delivery to the at least one third transistor.

One embodiment provides a method comprising etching a fin of a fin-shaped field effect transistor (FinFET) to form a reduced fin, and laterally etching the reduced fin to form a fin channel including a first fin channel sidewall and a second fin channel sidewall opposing the first fin channel sidewall. The method further comprises forming a first thin dielectric tunnel and a second thin dielectric tunnel on the first fin channel sidewall and the second fin channel sidewall, respectively. Each thin dielectric tunnel prevents lateral epitaxial crystal growth on the fin channel. The method further comprises etching an insulator layer disposed between the fin channel and a substrate of the FinFET to expose portions of a substrate surface of the substrate. A source epitaxy and a drain epitaxy are formed from vertical epitaxial crystal growth on the exposed portions of the substrate surface after epitaxial deposition.