Influence of the Gate Oxide and Back Oxide Material Types on Self-heating Effect in Junctionless FinFET

In this work, the self-heating effect on the Junctionless FinFET is investigated. The dependence of lattice temperature in the channel center of the transistor on the thickness of gate oxide as well as back oxide is simulated. Different types of the most used oxide materials $\left(\mathrm{SiO}_{2}, \mathbf{H f O}_{\mathbf{2}}\right.$, and $\mathrm{Si}_{3} \mathrm{~N}_{4}$) and their combinations are considered for gate and back oxides. 3D simulation is performed using Sentaurus TCAD. It is shown, that the lattice temperature mainly monotonically decreased with the increasing gate oxide thickness. However, the lattice temperature is monotonically increased with increasing the thickness of the back oxide. The dependence of the lattice temperature in the center of the channel on the back oxide thickness is in agreement with the known model. This behavior of the lattice temperature depends on the relation between heat generation and dissipation rates in the transistor channel. The obtained behavior of the lattice temperature is explained by a difference in the heat conductivity of the oxide materials. Also, the lattice temperature dependence on the gate oxide thickness is explained by the increase of the contact area between gate oxide and the gate with increasing the gate oxide thickness. Besides this, it is accounted that the Joule heat generation rate depends on drain current, which also depends on oxide materials.