Design optimization of sub-5 nm node nanosheet field effect transistors to minimize self-heating effects
Journal of Vacuum Science and Technology B
In this work, self-heating effects (SHE) in nanometer-scale metal-oxide-semiconductor field-effect transistor structures-namely, FinFETs (FFs), nanosheet gate-All-Around FETs (NSFs), and nanowire gate-All-Around FETs (GAAFs)-are investigated via three-dimensional device electrothermal simulations using technology computer-Aided design software tools. Initially, transistor design parameter values are set so that their on-state currents are similar for the same operating voltage (VDD). It is found that NSFs and GAAFs are more susceptible to SHE and that p-channel transistors have higher peak internal temperatures than do their n-channel counterparts due to the poor thermal conductivity of the silicon-germanium used as the p-Type source/drain material. Subsequently, the on-state currents of FFs, NSFs, and GAAFs are compared under the constraint of identical peak internal temperature, which is required to ensure long-Term reliability, revealing that NSFs and GAAFs offer no performance advantage over FFs under this constraint. Design optimization of p-channel NSFs for minimal SHE is subsequently investigated. It is found that with such optimization, NSFs operating at lower VDD (for similar SHE) can achieve similar on-state current as FFs.
Fei Ding, Hiu Yung Wong, and Tsu Jae King Liu. "Design optimization of sub-5 nm node nanosheet field effect transistors to minimize self-heating effects" Journal of Vacuum Science and Technology B (2021). https://doi.org/10.1116/6.0000675