Effect of oxide thickness scaling on self-heating in graphene transistors

Recent studies using infrared (IR) imaging of graphene transistors [1,2] have revealed substantial Joule heating under realistic operating conditions for graphene-on-insulator (GOI) devices. Here we use simulations calibrated against experimental data to examine the trends of performance degradation caused by self-heating as a function of insulator (SiO2) thickness. We also examine both unipolar and ambipolar operating conditions, and find that peak channel temperatures are proportional to oxide thickness for the unipolar case (as would be expected), but for ambipolar operation an optimum oxide substrate thickness exists (∼80 nm) which minimizes peak temperature, due to competing electrostatic and thermal effects.