Reducing graphene-metal contact resistance via laser nano-welding

Rainer Kling, K. Keramatnejad, Y. S. Zhou, D. W. Li, H. Rabiee Golgir, X. Huang, J. F. Song, S. Ducharme, Y. F. Lu

Research output: Chapter in Book/Report/Conference proceedingConference contribution

3 Scopus citations


Performance of the graphene-based devices is usually limited by the large electrical contact resistance at the graphenemetal junctions. In this work, a laser nano-welding method has been developed in order to reduce the graphene-metal contact resistances by improving the carrier injection at the junctions. Laser-induced breakdown of C-C bonds was performed at the edges of graphene-metal contact areas, to facilitate the bonding between the metallic atoms and graphene after the annealing process and, therefore, maximize the carrier transport. It is experimentally proved that the structural defects and open-ended C atoms are formed as a result of the laser irradiation performed at λ=514 nm and optical power of 20 mW. The edge-contacted junctions were then realized by an annealing step that followed the laser irradiation step. After this two-step treatment, contact resistance (£C) as low as 2.57 ω.μm2 is achieved, which is less than 6% of its pristine value and close to the 2015 International Technology Roadmap for Semiconductors (ITRS 2015; £C = 2.57 ω.μm2). Moreover, the site-selective nature of the proposed laser nano-welding method prevents degradation of the superior electrical properties of the graphene channel which is considered a common limitation in most of approaches proposed for achieving a reproducible low graphene-metal contact resistance.

Original languageEnglish (US)
Title of host publicationLaser-Based Micro- and Nanoprocessing XI
EditorsUdo Klotzbach, Rainer Kling, Kunihiko Washio
ISBN (Electronic)9781510606258
StatePublished - 2017
EventLaser-Based Micro- and Nanoprocessing XI 2017 - San Francisco, United States
Duration: Jan 31 2017Feb 2 2017

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


OtherLaser-Based Micro- and Nanoprocessing XI 2017
Country/TerritoryUnited States
CitySan Francisco


  • Suspended grapheme
  • contact resistance
  • edge contact
  • laser irradiation

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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