In a method of manufacturing a semiconductor device, a fin structure in which first semiconductor layers and second semiconductor layers are alternately stacked is formed, a sacrificial gate structure is formed over the fin structure, a source/drain region of the fin structure, which is not covered by the sacrificial gate structure, is etched, thereby forming a source/drain space, the first semiconductor layers are laterally etched through the source/drain space, and a source/drain epitaxial layer is formed in the source/drain space. An inner spacer made of a dielectric material is formed on an end of each of the etched first semiconductor layers and at least one of the spacer has width changes along vertical direction of device. At least one of the first semiconductor layers has a composition different from another of the first semiconductor layers.

A semiconductor device includes a first transistor in a first region of a substrate and a second transistor in a second region of the substrate. The first transistor includes multiple first semiconductor patterns; a first gate electrode; a first gate dielectric layer; a first source/drain region; and an inner-insulating spacer. The second transistor includes multiple second semiconductor patterns; a second gate electrode; a second gate dielectric layer; and a second source/drain region. The second gate dielectric layer extends between the second gate electrode and the second source/drain region and is in contact with the second source/drain region. The first source/drain region is not in contact with the first gate dielectric layer.

Neighboring gate-all-around integrated circuit structures having a conductive contact stressor between epitaxial source or drain regions are described. In an example, a first vertical arrangement of nanowires and a second vertical arrangement of nanowires above a substrate. A first gate stack is over the first vertical arrangement of nanowires. A second gate stack is over the second vertical arrangement of nanowires. First epitaxial source or drain structures are at ends of the first vertical arrangement of nanowires. Second epitaxial source or drain structures are at ends of the second vertical arrangement of nanowires. An intervening conductive contact structure is between neighboring ones of the first epitaxial source or drain structures and of the second epitaxial source or drain structures. The intervening conductive contact structure imparts a stress to the neighboring ones of the first epitaxial source or drain structures and of the second epitaxial source or drain structures.

A metallic single-walled carbon nanotube (SWNT) hybrid assembly or superstructure includes a single walled carbon nanotube (SWNT) having a chiral index (n, m) where (nm)/3 is an integer or 0; and an oligomer or polymer that single-chain wraps the metallic SWNT, wherein the oligomer or polymer is formed of repeat units, wherein each repeat unit has at least one charged functional group per 1-3 nm of oligomer or polymer length. The superstructure is suitable for optical, electro-optical, and spintronic-based device applications.

A field effect transistor (FET) includes a substrate; a channel material located on the substrate, the channel material comprising one of graphene or a nanostructure; a gate located on a first portion of the channel material; and a contact aligned to the gate, the contact comprising one of a metal silicide, a metal carbide, and a metal, the contact being located over a source region and a drain region of the FET, the source region and the drain region comprising a second portion of the channel material.

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.

A method for synthesizing noble metal-semiconductor heterostructures includes the following steps S1 to S6. Step S1: noble metal seeds are formed. Step S2: at least one metal precursors including a first metal and a first solvent are mixed in a first reactor chamber, so as to obtain a first solution comprising a first mixture. Step S3: the first solution is heated with a first heating process, so as to obtain a transparent solution. Step S4: the noble metal seeds, the transparent solution, and a second solvent are mixed, so as to obtain a second solution. Step S5: the second solution is heated with a second heating process to grow a semiconductor structure containing the first metal on the noble metal seeds, thereby forming the noble metal-semiconductor heterostructures therein. Also, a photocatalytic system including the aforesaid noble metal-semiconductor heterostructures is provided.

A process for etching a substrate comprising polycrystalline silicon to form silicon nanostructures includes depositing metal on top of the substrate and contacting the metallized substrate with an etchant aqueous solution comprising about 2 to about 49 weight percent HF and an oxidizing agent.

The present invention provides a field effect transistor and the method for preparing such a filed effect transistor. The filed effect transistor comprises a semiconductor, germanium nanowires, a first III-V compound layer surrounding the germanium nanowires, a semiconductor barrier layer, a gate dielectric layer and a gate electrode sequentially formed surrounding the first III-V compound layer, and source/drain electrodes are respectively located at each side of the gate electrode and on the first III-V compound layer. According to the present invention, the band width of the barrier layer is greater than that of the first III-V compound layer, and the band curvatures of the barrier layer and the first III-V compound layer are different, therefore, a two-dimensional electron gas (2DEG) is formed in the first III-V compound layer near the barrier layer boundary. Since the 2DEG has higher mobility, the performance of the filed effect transistor improved. Besides, the performance of the filed effect transistor also improved due to the structure is a gate-all-around structure.

A semiconductor device may include a strain relaxed buffer layer provided on a substrate to contain silicon germanium, a semiconductor pattern provided on the strain relaxed buffer layer to include a source region, a drain region, and a channel region connecting the source region with the drain region, and a gate electrode enclosing the channel region and extending between the substrate and the channel region. The source and drain regions may contain germanium at a concentration of 30 at % or higher.