A method is provided for forming Group IIIA-nitride layers, such as GaN, on substrates. The Group IIIA-nitride layers may be deposited on mesa-patterned semiconductor-on-insulator (SOI, e.g., silicon-on-insulator) substrates. The Group IIIA-nitride layers may be deposited by heteroepitaxial deposition on mesa-patterned semiconductor-on-insulator (SOI, e.g., silicon-on-insulator) substrates.

A semiconductor structure (100) comprising: a substrate (102), a first layer (106) of Al.sub.XGa.sub.YIn.sub.(1−X−Y)N disposed on the substrate, stacks (107, 109) of several second and third layers (108, 110) alternating against each other, between the substrate and the first layer, a fourth layer (112) of Al.sub.XGa.sub.YIn.sub.(1−X−Y)N, between the stacks, a relaxation layer of AlN disposed between the fourth layer and one of the stacks, and, in each of the stacks: the level of Ga of the second layers increases from one layer to the next in a direction from the substrate to the first layer, the level of Ga of the third layers is constant or decreasing from one layer to the next in said direction, the average mesh parameter of each group of adjacent second and third layers increasing from one group to the next in said direction, the thickness of the second and third layers is less than 5 nm.

The invention relates to a method for producing a semiconductor structure, characterised in that the method comprises a step (201) of depositing a crystalline passivation layer continuously covering the entire surface of a layer based on group III nitrides, said crystalline passivation layer, which is deposited from a precursor containing silicon atoms and a flow of nitrogen atoms, consisting of silicon atoms bound to the surface of the layer based on group III nitrides and arranged in a periodical arrangement such that a diffraction image of said crystalline passivation layer obtained by grazing-incidence diffraction of electrons in the direction [1-100] comprises: two fractional order diffraction lines (0, −⅓) and (0, −⅔) between the central line (0, 0) and the integer order line (0, −1), and two fractional order diffraction lines (0, ⅓) and (0, ⅔) between the central line (0, 0) and the integer order line (0, 1).

A method of depositing a silicon film on a recess formed in a surface of a substrate is provided. The substrate is placed on a rotary table in a vacuum vessel, so as to pass through first, second, and third processing regions in the vacuum vessel. An interior of the vacuum vessel is set to a first temperature capable of breaking an Si—H bond. In the first processing region, Si.sub.2H.sub.6 gas having a temperature less than the first temperature is supplied to form an SiH.sub.3 molecular layer on its surface. In the second processing region, a silicon atomic layer is exposed on the surface of the substrate, by breaking the Si—H bond in the SiH.sub.3 molecular layer. In the third processing region, by anisotropic etching, the silicon atomic layer on an upper portion of an inner wall of the recess is selectively removed.

An integrated circuit device is provided that includes a first fin structure and a second fin structure extending from a substrate. The first fin structure is a first composition, and includes rounded corners. The second fin structure is a second composition, different than the first composition. A first interface layer is formed directly on the first fin structure including the rounded corners and a second interface layer directly on the second fin structure. The first interface layer is an oxide of the first composition and the second interface layer is an oxide of the second composition. A gate dielectric layer is formed over the first interface layer and the second interface layer.

A field-effect transistor and method for fabricating such a field-effect transistor that utilizes an air-sensitive two-dimensional material (e.g., silicene). A film of air-sensitive two-dimensional material is deposited on a crystalized metallic (e.g., Ag) thin film on a substrate (e.g., mica substrate). A capping layer of insulating material (e.g., aluminum oxide) is deposited on the air-sensitive two-dimensional material. The substrate is detached from the metallic thin film/air-sensitive two-dimensional material/insulating material stack structure. The metallic thin film/air-sensitive two-dimensional material/insulating material stack structure is then flipped. The flipped metallic thin film/air-sensitive two-dimensional material/insulating material stack structure is attached to a device substrate followed by having the metallic thin film etched to form contact electrodes. In this manner, the pristine properties of air-sensitive two-dimensional materials are preserved from degradation when exposed to air. Furthermore, this new technique allows safe transfer and device fabrication of air-sensitive two-dimensional materials with a low material and process cost.

Structures described herein may include mechanically bonded interlayers for formation between a first Group III-V semiconductor layer and a second semiconductor layer. The mechanically bonded interlayers provide reduced lattice strain by strain balancing between the Group III-V semiconductor layer and the second semiconductor layer, which may be silicon.

A method of forming Si or Ge-based and III-V based vertically integrated nanowires on a single substrate and the resulting device are provided. Embodiments include forming first trenches in a Si, Ge, III-V, or Si.sub.xGe.sub.1-x substrate; forming a conformal SiN, SiO.sub.xC.sub.yN.sub.z layer over side and bottom surfaces of the first trenches; filling the first trenches with SiO.sub.x; forming a first mask over portions of the Si, Ge, III-V, or Si.sub.xGe.sub.1-x substrate; removing exposed portions of the Si, Ge, III-V, or Si.sub.xGe.sub.1-x substrate, forming second trenches; forming III-V, III-V.sub.xM.sub.y, or Si nanowires in the second trenches; removing the first mask and forming a second mask over the III-V, III-V.sub.xM.sub.y, or Si nanowires and intervening first trenches; removing the SiO.sub.x layer, forming third trenches; and removing the second mask.

A method of fabricating a semiconductor device includes implanting dopants into a silicon substrate, and performing a thermal anneal process that activates the implanted dopants. In response to activating the implanted dopants, a layer of ultra-thin single-crystal silicon is formed in a portion of the silicon substrate. The method further includes performing a heteroepitaxy process to grow a semiconductor material from the layer of ultra-thin single-crystal silicon.

A semiconductor-on-insulator substrate for use in RF applications, such as a silicon-on-insulator substrate, comprises a semiconductor top layer, a buried oxide layer and a passivation layer over a support substrate. In addition, a penetration layer is provided between the passivation layer and the silicon support substrate to ensure sufficient high resistivity below RF features and avoid increased migration of dislocations in the support substrate. RE devices may be fabricated on and/or in such a semiconductor-on-insulator substrate.