Semiconductor device and manufacturing method therefor

A method for manufacturing a semiconductor device, comprising:

• providing a substrate structure comprising a substrate and a first material layer on the substrate, wherein a recess is formed in the substrate and the first material layer comprises a nanowire spanning and suspended above the recess;
• forming a base layer on the substrate structure, wherein the base layer comprises at least a first portion covering an exposed surface of the nanowire and a second portion covering an exposed surface of the recess;
• selectively growing a graphene layer on the base layer;
• forming a second dielectric layer on the graphene layer;
• forming an electrode material layer on the substrate structure to cover the second dielectric layer;
• partially removing the electrode material layer, the second dielectric layer, and the graphene layer so as to define an area of an active region wherein at least a portion of a stack layer of the electrode material layer, the second dielectric layer, and the graphene layer on the nanowire remains and is within the active region;
• and
• forming a gate by etching at least a portion of the stack layer remaining within the active region to at least the second dielectric layer so as to form a gate structure surrounding an intermediate portion of the nanowire, wherein the gate structure comprises a portion of the electrode material layer and the second dielectric layer.