Electron Transport in Graphene-Versus Al/Pd-Coated Thin Cu Films With Low-Surface Roughness: A First Principles Study

IEEE Access

Erping Li¹  Yongjian Li²  Manareldeen Ahmed² 

[1] College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, China;State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin, China;

关键词: Thin films;    surface scattering;    copper;    graphene;    electron transport;   

DOI  :  10.1109/ACCESS.2019.2925459

来源: DOAJ

【 摘 要 】

Surface scattering is a major issue in thin Cu films at reduced scales. The rise in the diffusive scattering due to the surface roughness causes the electrical resistance to increase remarkably. In this paper, graphene, as opposed to Al and Pd, is considered as a liner layer for thin Cu film with low-surface roughness using first principles calculation. The surface roughness is simulated using the nonequilibrium coherent potential approximation combined with the linear muffin-tin orbital formulation. The coherent potential approximation band structure shows that the graphene π-bands is not significantly affected by the surface disorder at the Cu surface and that graphene acts as a parallel path to the electrons. On the other hand, the bands of Cu-Al/Pd around the Fermi level are substantially broadened due to the surface disorder. Moreover, the graphene-coated Cu shows less electrical resistance than Al/Pd-coated Cu for surface disorder x ≲̰ 5% for thin films with 0.245 nm in width, and 1.23 nm in thickness. The enhancement in the transport properties in Cu-Gr is attributed to the weak electronic interaction at the interface. The obtained results suggest that graphene is better than Al and Pd as a liner material for thin Cu films.

【 授权许可】

Unknown