▎ 摘　　要

NOVELTY - The structure has an insulator material on a vertical sidewall of a mesa on a substrate (50). The insulator material spans an entirety of a height and a width of the vertical sidewall of the mesa. A graphene has a thickness of one atom adjacent the insulator material. The graphene spans an entirety of a height and a width of the insulator material. The graphene is directly adjacent the insulator material. The another insulator material on another vertical sidewall of the mesa spans an entirety of a height and a width of the another vertical sidewall of the mesa. USE - Semiconductor device structure such as vertical field effect transistor (VFET) structure. ADVANTAGE - The channel region allows current to flow between a source region and a drain region. The re-filled material can be configured to withstand, without deformation, higher fabrication temperatures than the metal seeds could withstand. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) semiconductor device; and (2) method of forming a semiconductor device. DESCRIPTION OF DRAWING(S) - The drawing shows a top and front perspective view of semiconductor device structure. Substrate (50) Metal seed (110) Gate conductor (150) First gate insulator (160) Second insulator material (180)