▎ 摘　　要

We use infrared thermal imaging and electrothermal simulations to find that localized Joule heating in graphene field-effect transistors on SiO2 Is primarily governed by device electrostatics. Hot spots become more localized (i.e., sharper) as the underlying oxide thickness Is reduced, such that the average and peak device temperatures scale differently, with significant long-term reliability implications. The average temperature is proportional to oxide thickness, but the peak temperature is minimized at an oxide thickness of similar to 90 nm due to competing electrostatic and thermal effects. We also find that careful comparison of high-field transport models with thermal Imaging can be used to shed light on velocity saturation effects. The results shed light on optimizing heat dissipation and reliability of graphene devices and Interconnects.