Impact of Nanosheet Pitch, Ambient Temperature, and Thermal Contact Resistance on Electrothermal Characteristics of Vertical Gate-All-Around Nanosheet FETs

In this paper, the impact of thermal boundary conditions on self-heating effect (SHE) of vertical gate-all-around nanosheet FETs (VGAAFETs) is investigated using the calibrated TCAD. The hydrodynamic model, density gradient quantization model, thin-layer mobility model and etc. are adopted to accurately capture the electrothermal behaviors. The results show that electrothermal characteristics strongly affected by ambient temperature. Besides, thermal coupling among nanosheets is enhanced as the pitch of nanosheets becomes smaller. As the via density decreases, the chief heat removal exit has changed from drain to substrate for the nonadiabatic drain-top VGAAFET. Moreover, the drain-top configuration endures less SHE degeneration but presents smaller driving current than the source-top one.