Electric field management techniques in GaN based semiconductors that utilize patterned regions of differing conductivity under the active GaN device, such as a GaN high electron mobility transistor (HEMT), are described. As an example, a patterned layer of oxidized silicon can be formed superjacent a layer of silicon dioxide during or prior to the heteroepitaxy of GaN or another semiconductor material. These techniques can be useful for back-side electric field management because a silicon layer, for example, can be made conductive to act as a back-side field plate.

A semiconductor device includes a graphene film disposed on a substrate and formed of atomic layers of graphene that are stacked, a source electrode and a drain electrode disposed on the graphene film, and a gate electrode disposed on the graphene film between the source electrode and the drain electrode with a gate insulator film interposed between the gate electrode and the graphene film, wherein a first number of the atomic layers of the graphene film in a source region where the source electrode is located and a drain region where the drain electrode is located is greater than a second number of the atomic layers of the graphene film in a channel region where the gate electrode is located.

A semiconductor structure is provided that includes a silicon germanium alloy fin having a second germanium content located on a first portion of a substrate. The structure further includes a laterally graded silicon germanium alloy material portion located on a second portion of the substrate. The laterally graded silicon germanium alloy material portion is spaced apart from the silicon germanium alloy fin and has end portions having the second germanium content and a middle portion located between the end portions that has a first germanium content that is less than the second germanium content.

A laminated body includes: a substrate portion composed of silicon carbide; and a graphene film disposed on a first main surface of the substrate portion, the graphene film having an atomic arrangement oriented with respect to an atomic arrangement of the silicon carbide of the substrate portion. A region in which a value of G/G in Raman spectrometry is not less than 1.2 is not less than 10% in an area ratio in an exposed surface of the graphene film, the exposed surface being a main surface of the graphene film opposite to the substrate portion.

In various embodiments, a method of forming a graphene structure is provided. The method may include forming a body including at least one protrusion, and forming a graphene layer at an outer peripheral surface of the at least one protrusion.

A semiconductor structure is provided that includes a silicon germanium alloy fin having a second germanium content located on a first portion of a substrate. The structure further includes a laterally graded silicon germanium alloy material portion located on a second portion of the substrate. The laterally graded silicon germanium alloy material portion is spaced apart from the silicon germanium alloy fin and has end portions having the second germanium content and a middle portion located between the end portions that has a first germanium content that is less than the second germanium content.

The present invention relates to a transparent compound semiconductor and to a production method therefor, and is adapted to provide a transparent compound semiconductor of high stability and charge mobility while being transparent. The transparent compound semiconductor according to the present invention has a composition of Ba.sub.1XLa.sub.XSnO.sub.3 (0<x<0.1) and has a charge mobility of at least 10 cm.sup.2/V.Math.sec.

The invention pertains to formation of a semiconducting portion (60) by epitaxial growth on a strained germination portion (40), comprising the steps in which a cavity (21) is produced under a structured part (11) by rendering free a support layer (30) situated facing the structured part (11), a central portion (40), termed the strained germination portion, then being strained; and a semiconducting portion (60) is formed by epitaxial growth on the strained germination portion (40), wherein the structured part (11) is furthermore placed in contact with the support layer (30) in such a way as to bind the structured part (11) of the support layer.

A 3CSiC buffer layer on Si(001) comprising a porous buffer layer of 3CSiC on a Si(001) substrate, wherein the porous buffer layer is produced through a solid state reaction, and wherein an amorphous carbon layer on the Si(001) substrate is deposited by magnetron sputtering of a C target at room temperature at a rate of 0.8 nm/min.

In various embodiments, a method of forming a graphene structure is provided. The method may include forming a body including at least one protrusion, and forming a graphene layer at an outer peripheral surface of the at least one protrusion.