Dependable Contact Related Parameter Extraction in Graphene–Metal Junctions

RWTH Publications (RWTH Aachen)

Abstract

Abstract The accurate extraction and the reliable, repeatable reduction of graphene–metal contact resistance ( R C ) are still open issues in graphene technology. Here, the importance of following clear protocols when extracting R C using the transfer length method (TLM) is demonstrated. The example of back‐gated graphene TLM structures with nickel contacts, a complementary metal oxide semiconductor compatible metal, is used here. The accurate extraction of R C is significantly affected by generally observable Dirac voltage shifts with increasing channel lengths in ambient conditions. R C is generally a function of the carrier density in graphene. Hence, the position of the Fermi level and the gate voltage impact the extraction of R C . Measurements in high vacuum, on the other hand, result in dependable extraction of R C as a function of gate voltage owing to minimal spread in Dirac voltages. The accurate measurement and extraction of important parameters like contact‐end resistance, transfer length, sheet resistance of graphene under the metal contact, and specific contact resistivity as a function of the back‐gate voltage is further assessed. The presented methodology has also been applied to devices with gold and copper contacts, with similar conclusions.

Authors 8

1. Amit Gahoi Aachen Faculty of Electrical Engineering and Information Technology Chair of Electronic Devices

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University, Faculty of Electrical Engineering and Information Technology, Chair of Electronic Devices, Otto-Blumenthal-Str. 2, Aachen, 52074 Germany

2. Satender Kataria Aachen Faculty of Electrical Engineering and Information Technology Chair of Electronic Devices

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University, Faculty of Electrical Engineering and Information Technology, Chair of Electronic Devices, Otto-Blumenthal-Str. 2, Aachen, 52074 Germany

3. F. Driussi

   University of Udine

   Affiliation as printed

   Universitá degli Studi di Udine Dipartimento Politecnico di Ingegneria e Architettura (DPIA) Via delle Scienze 206 Udine 33100 Italy

4. Stefano Venica

   University of Udine

   Affiliation as printed

   Universitá degli Studi di Udine Dipartimento Politecnico di Ingegneria e Architettura (DPIA) Via delle Scienze 206 Udine 33100 Italy

5. Himadri Pandey Aachen Faculty of Electrical Engineering and Information Technology Chair of Electronic Devices

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University, Faculty of Electrical Engineering and Information Technology, Chair of Electronic Devices, Otto-Blumenthal-Str. 2, Aachen, 52074 Germany

6. David Esseni

   University of Udine

   Affiliation as printed

   Universitá degli Studi di Udine Dipartimento Politecnico di Ingegneria e Architettura (DPIA) Via delle Scienze 206 Udine 33100 Italy

7. L. Selmi

   University of Modena and Reggio Emilia

   Affiliation as printed

   Universitá degli Studi di Modena e Reggio Emilia Dipartimento di Ingegneria “Enzo Ferrari” Via Vivarelli 10 Modena 41125 Italy

8. Max C. Lemme corresponding Aachen AMO GmbH Advanced Microelectronic Center Aachen Faculty of Electrical Engineering and Information Technology Chair of Electronic Devices

   AMO (Germany) · RWTH Aachen University

   Affiliation as printed

   AMO GmbH, Advanced Microelectronic Center Aachen (AMICA), Otto-Blumenthal-Str. 25, Aachen, 52074 Germany

   RWTH Aachen University, Faculty of Electrical Engineering and Information Technology, Chair of Electronic Devices, Otto-Blumenthal-Str. 2, Aachen, 52074 Germany