Monte Carlo study of apparent mobility reduction in nano-MOSFETs

TL;DR

This paper uses Monte Carlo simulations to analyze apparent mobility reduction in nano-MOSFETs, attributing it to non-stationary effects and modeling it with a Mathiessen-like approach, aligning well with experimental data.

Contribution

It demonstrates that mobility reduction in nano-MOSFETs can be explained without added scattering phenomena, highlighting non-stationary effects as the cause.

Findings

Mobility decreases with channel length at room temperature.

Non-stationary effects cause the apparent mobility reduction.

A Mathiessen-like model accurately reproduces simulation and experimental results.

Abstract

The concept of mobility is discussed in the case of unstrained and strained nanoscale DG MOSFET thanks to particle Monte Carlo device simulation. Without the introduction of specific scattering phenomenon for short channel devices, the apparent mobility extracted from simulated electrical characteristics decreases with the shrinking of the channel length, as experimentally observed elsewhere. We show that this reduction at room temperature is caused by non stationary effects. Moreover, both simulation results and experimental data may be well reproduced by a Mathiessen-like model, using a "ballistic mobility" extracted from MC simulations together with the usual long channel mobility.