A method for making a field effect transistor includes providing a graphene nanoribbon composite structure. The graphene nanoribbon composite structure includes a substrate and a plurality of graphene nanoribbons spaced apart from each other. The substrate includes a plurality of protrusions spaced apart from each other, and one of the plurality of graphene nanoribbons is on the substrate and between two adjacent protrusions. An interdigital electrode is placed on the graphene nanoribbon composite structure, and the interdigital electrode covers the plurality of protrusions and is electrically connected to the plurality of graphene nanoribbons.

A method for making a field effect transistor includes providing a graphene nanoribbon composite structure. The graphene nanoribbon composite structure includes a substrate and a plurality of graphene nanoribbons spaced apart from each other. The plurality of graphene nanoribbons are located on the substrate and extend substantially along a same direction, and each of the plurality of graphene nanoribbons includes a first end and a second end opposite to the first end. A source electrode is formed on the first end, and a drain electrode is formed on the second end. The source electrode and the drain electrode are electrically connected to the plurality of graphene nanoribbons. An insulating layer is formed on the plurality of graphene nanoribbons, and the plurality of graphene nanoribbons are between the insulating layer and the substrate. A gate is formed on a surface of the insulating layer away from the substrate.

An electrical isolation process, includes receiving a substrate including a layer of carbon-rich material on silicon, and selectively removing regions of the substrate to form mutually spaced islands of the carbon-rich material on the silicon. The layer of carbon-rich material on silicon includes the layer of carbon-rich material on an electrically conductive layer of silicon on an electrically insulating material. Selectively removing regions of the substrate includes removing the carbon-rich material and at least a portion of the electrically conductive layer of silicon from those regions to provide electrical isolation between the islands of carbon-rich material on silicon.

In some embodiments, a semiconductor structure can include: a diamond substrate having a surface conductive layer; a heavily doped region formed in the diamond substrate; and a metal contact positioned over the conductive surface layer such that a first portion of the heavily doped region is covered by the metal contact and a second portion of the heavily doped region is not covered by the metal contact.

A silicon layer etchant composition and associated methods, the composition including about 1 wt % to about 20 wt % of an alkylammonium hydroxide; about 1 wt % to about 30 wt % of an amine compound; about 0.01 wt % to about 0.2 wt % of a nonionic surfactant including both a hydrophobic group and a hydrophilic group; and water, all wt % being based on a total weight of the silicon layer etchant composition.

The present disclosure relates to a semiconductor structure and a manufacturing method thereof. The method of manufacturing a semiconductor structure includes: providing a base; forming a plurality of first trenches arranged in parallel at intervals and extending along a first direction, and an initial active region between two adjacent ones of the first trenches, wherein the initial active region includes a first initial source-drain region close to a bottom of the first trench, a second initial source-drain region away from the bottom of the first trench, and an initial channel region located between the first initial source-drain region and the second initial source-drain region; forming a protective dielectric layer, wherein the protective dielectric layer covers a sidewall of the second initial source-drain region and a sidewall of the initial channel region; thinning the first initial source-drain region.

An optical device includes a gallium and nitrogen containing substrate comprising a surface region configured in a (20-2-1) orientation, a (30-3-1) orientation, or a (30-31) orientation, within +/−10 degrees toward c-plane and/or a-plane from the orientation. Optical devices having quantum well regions overly the surface region are also disclosed.

The present invention provides a method of manufacturing a graphene transistor 101, the method comprising: (a) providing a substrate having a substantially flat surface, wherein the surface comprises an insulating region 110 and an adjacent semiconducting region 105; (b) forming a graphene layer structure 115 on the surface, wherein the graphene layer structure is disposed on and across a portion of both the insulating region and the adjacent semiconducting region; (c) forming a layer of dielectric material 120 on a portion of the graphene layer structure which is itself disposed on the semiconducting region 105; and (d) providing: a source contact 125 on a portion of the graphene layer structure which is itself disposed on the insulating region 110; a gate contact 130 on the layer of dielectric material 120 and above a portion of the graphene layer structure which is itself disposed on the semiconducting region 105; and a drain contact 135 on the semiconducting region 105 of the substrate surface.

There is provided a method of manufacturing a transistor, the method comprising: (a) providing a substrate having a semiconductor surface; (b) providing a graphene layer structure on a first portion of the semiconductor surface, wherein the graphene layer structure has a thickness of n graphene monolayers, wherein n is at least 2; (c) etching a first portion of the graphene layer structure to reduce the thickness of the graphene layer structure in said first portion to from n−1 to 1 graphene monolayers; (d) forming a layer of dielectric material on the first portion of the graphene layer structure; and (e) providing: a source contact on a second portion of the graphene layer structure; a gate contact on the layer of dielectric material; and a drain contact on a second portion of the semiconductor surface of the substrate.

An optical device includes a gallium and nitrogen containing substrate comprising a surface region configured in a (20-2-1) orientation, a (30-3-1) orientation, or a (30-31) orientation, within +/−10 degrees toward c-plane and/or a-plane from the orientation. Optical devices having quantum well regions overly the surface region are also disclosed.