A method for fabricating a semiconductor device having a substantially undoped channel region includes forming a plurality of fins extending from a substrate. In various embodiments, each of the plurality of fins includes a portion of a substrate, a portion of a first epitaxial layer on the portion of the substrate, and a portion of a second epitaxial layer on the portion of the first epitaxial layer. The portion of the first epitaxial layer of each of the plurality of fins is oxidized, and a liner layer is formed over each of the plurality of fins. Recessed isolation regions are then formed adjacent to the liner layer. The liner layer may then be etched to expose a residual material portion (e.g., Ge residue) adjacent to a bottom surface of the portion of the second epitaxial layer of each of the plurality of fins, and the residual material portion is removed.

A semiconductor device and a method of forming the same, the semiconductor device includes a fin shaped structure, agate structure, an epitaxial layer, an interlayer dielectric layer, a first plug and a protection layer. The fin shaped structure is disposed on a substrate, and the gate structure is across the fin shaped structure. The epitaxial layer is disposed in the fin shaped structure, adjacent to the gate structure. The interlayer dielectric layer covers the substrate and the fin shaped structure. The first plug is formed in the interlayer dielectric layer, wherein the first plug is electrically connected to the epitaxial layer. The protection layer is disposed between the first plug and the gate structure.

A FinFET includes a substrate, a plurality of insulators disposed on the substrate, a gate stack and a strained material. The substrate includes at least one semiconductor fin and the semiconductor fin includes at least one modulation portion distributed therein. The semiconductor fin is sandwiched by the insulators. The gate stack is disposed over portions of the semiconductor fin and over portions of the insulators. The strained material covers portions of the semiconductor fin that are revealed by the gate stack. In addition, a method for fabricating the FinFET is provided.

A FinFET including a substrate, a plurality of insulators and a gate stack is provided. The substrate includes a plurality of trenches and at least one semiconductor fin between the trenches. The insulators are disposed in the trenches. The semiconductor fin includes a first portion embedded between the insulators; a necking portion disposed on the first portion, the necking portion being uncovered by the insulators; and a second portion disposed on the necking portion, wherein a width of the necking portion is less than a width of the first portion. The gate stack partially covers the semiconductor fin, the at least one recess and the insulators.

Embodiments of the present invention provide transistor structures having strained channel regions. Strain is created through lattice mismatches in the source and drain regions relative to the channel region of the transistor. In embodiments of the invention, the transistor channel regions are comprised of germanium, silicon, a combination of germanium and silicon, or a combination of germanium, silicon, and tin and the source and drain regions are comprised of a doped III-V compound semiconductor material. Embodiments of the invention are useful in a variety of transistor structures, such as, for example, trigate, bigate, and single gate transistors and transistors having a channel region comprised of nanowires or nanoribbons.

A transistor device includes a gate structure disposed over a channel region of a semiconductor substrate. A source/drain recess is arranged in the semiconductor substrate alongside the gate structure. A doped silicon-germanium (SiGe) region is disposed within the source/drain recess and has a doping type which is opposite to that of the channel. An un-doped SiGe region is also disposed within the source/drain recess. The un-doped SiGe region underlies the doped SiGe region and comprises different germanium concentrations at different locations within the source/drain recess.

Some embodiments of the present disclosure relate to a high electron mobility transistor (HEMT) which includes a heterojunction structure arranged over a semiconductor substrate. The heterojunction structure includes a binary III/V semiconductor layer made of a first III-nitride material to act as a channel region of the e-HEMT, and a ternary III/V semiconductor layer arranged over the binary III/V semiconductor layer and made of a second III-nitride material to act as a barrier layer. Source and drain regions are arranged over the ternary III/V semiconductor layer and are spaced apart laterally from one another. A gate structure is arranged over the heterojunction structure and is arranged between the source and drain regions. The gate structure is made of a third III-nitride material. A first passivation layer is disposed about sidewalls of the gate structure and is made of a fourth III-nitride material.

Semiconductor devices are provided. A semiconductor device includes a fin protruding from a substrate. Moreover, the semiconductor device includes first and second gate structures on the fin, and an isolation region between the first and second gate structures. The isolation region includes first and second portions having different respective widths. Related methods of forming semiconductor devices are also provided.

A semiconductor device may include a substrate including an NMOS region and a PMOS region, and having a protrusion pattern; first and second gate structures respectively formed on the NMOS region and the PMOS region of the substrate, crossing the protrusion pattern, and extending along a first direction that is parallel to an upper surface of the substrate; first and second source/drain regions formed on both sides of the first and second gate structures; and first and second contact plugs respectively formed on the first and second source/drain regions, wherein the first contact plug and the second contact plug are asymmetric. Methods of manufacturing are also provided.

A method of fabricating a vertical field effect transistor including forming a first recess in a substrate; epitaxially growing a first drain from the first bottom surface of the first recess; epitaxially growing a second drain from the second bottom surface of a second recess formed in the substrate; growing a channel material epitaxially on the first drain and the second drain; forming troughs in the channel material to form one or more fin channels on the first drain and one or more fin channels on the second drain, wherein the troughs over the first drain extend to the surface of the first drain, and the troughs over the second drain extend to the surface of the second drain; forming a gate structure on each of the one or more fin channels; and growing sources on each of the fin channels associated with the first and second drains.