Monte Carlo device modeling of 3D n-FinFETs to investigate heat generation

Understanding heat generation in transistors is not only interesting from a physics perspective but is also crucial for addressing self-heating and ensuring the reliability of nanoscale devices. Although FinFETs exhibit superior electrostatics compared to traditional planar structures, they suffer from self-heating which is exacerbated by advanced scaling. Since it is challenging to measure heat conduction at the nanoscale, advanced TCAD simulations are essential for understanding how heat is generated and transferred in such small structures. In this work, a 3D Monte Carlo (MC) device simulator is employed to investigate the spatial profile of heat source inside an 18-nm gate length n-FinFET, which is further used to estimate the lattice temperature during nominal device operation. We find that the average electron energy peaks to roughly 0.8 eV near the drain end (electron temperature ~ 6000 K) and it decays to its equilibrium value over an energy-relaxation length of ~ 20 nm. Crucially, this heat source gives an elevated lattice temperature of 428 K near the drain end, while the entire channel also operates much above the ambient temperature of 300 K, whereas a hypothetical Gaussian heat source is shown to result in an inaccurate spatial profile of the lattice temperature. Our results show that the design of FinFETs for reliability must properly account for electron heating and electron-phonon scatterings throughout the device.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Electrical & Computer Engr

Grantor

University of Illinois Urbana-Champaign

Year dc:date

2025

Author dc:creator

• Dastider, Ankan Ghosh

Contributors dc:contributor

• Rakheja, Shaloo

• Monte Carlo
• Finfet
• Tcad
• Semiconductor Device
• Heat Generation
• Scattering

Statement dc:rights

• Copyright 2025 Ankan Dastider

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/129730

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F129730