Dominant scattering mechanisms and mobility peak in cryogenic 2D electron transport in Silicon (110) confinement by high-k oxides

2025/10/09 by Huang, Hsin-Wen, Fang, Xi-Jun, Chen, Edward +1
#Applied Physics (physics.app-ph) #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

paper · doi:10.48550/arxiv.2510.08220

Abstract

The performance of silicon nano-devices at cryogenic temperatures is critical for quantum computing technologies. Through multi-valley Monte Carlo simulations of Si (110) systems, we reveal a fundamental shift in electron transport physics at low temperatures. Phonon scattering becomes negligible, and mobility is instead dictated by a competition between remote Coulomb scattering (RCS) at low carrier densities and surface roughness scattering (SRS) at high densities. This competition creates a distinct peak in electron mobility. Furthermore, we demonstrate a critical design trade-off for high-κ dielectrics like HfO₂: while enhancing gate control, they introduce strong remote phonon scattering, which can suppress mobility. These findings provide essential guidelines for the material selection and design of next-generation cryogenic nano-devices.

Citations

• Localization landscape theory of disorder in semiconductors. III. Application to carrier transport and recombination in light emitting diodes
• FinFET-a self-aligned double-gate MOSFET scalable to 20 nm

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