A Parameter Extraction Methodology for Graphene Field-Effect-Transistors

Artikel i vetenskaplig tidskrift, 2023

Graphene field-effect transistors have now been around for more than a decade and their transfer characteristics extensively used for device characterization. Model parameters like low-field charge-carrier mobility and device contact/series resistance have often been the main interest. However, not until recently have the methods for device characterization themselves been the focus of research publications. In this paper, I report on a structured methodology for extracting and validating the extracted GFET model parameter values based on the physics of field-effect transistors in general and of graphene field-effect transistors in particular. During the extraction process the GFET resistance is divided into two parts, a constant part, and a gate-voltage-dependent part where the constant part often has been believed to represent the series/contact resistance. However, part of it depends on the channel length and contains first-order information about mobility degradation. Finally, I show that the main influence of the quantum capa­citance can be captured by an equivalent oxide thickness replacing the insulator thickness.