Role of Joule Heating on Current Saturation and Transient Behavior of Graphene Transistors

TL;DR

This paper uses simulations to analyze how Joule heating affects current saturation and transient response in graphene transistors, revealing that self-heating influences device performance and can be mitigated by structural modifications.

Contribution

It provides new insights into the role of Joule heating in graphene transistors' current saturation and transient behavior through detailed simulations.

Findings

Self-heating partly causes current saturation in graphene transistors.

Heating degrades current densities by up to 15%.

Reducing insulator thickness or partial heat sinking improves performance.

Abstract

We use simulations to examine current saturation in sub-micron graphene transistors on SiO2/Si. We find self-heating is partly responsible for current saturation (lower output conductance), but degrades current densities >1 mA/um by up to 15%. Heating effects are reduced if the supporting insulator is thinned, or in shorter channel devices by partial heat sinking at the contacts. The transient behavior of such devices has thermal time constants of ~30-300 ns, dominated by the thickness of the supporting insulator and that of device capping layers (a behavior also expected in ultrathin body SOI transistors). The results shed important physical insight into the high-field and transient behavior of graphene transistors.