Comprehensive studies on steady-state and transient electronic transport in In0.52Al0.48As

TL;DR

This paper provides a detailed simulation-based analysis of steady-state and transient electronic transport in In0.52Al0.48As, revealing how transient effects influence device performance and cut-off frequencies at nanometer scales.

Contribution

It offers a comprehensive characterization of electronic transport parameters and transient effects in In0.52Al0.48As, aiding optimized device design for high-frequency applications.

Findings

Transient effects are significant for device lengths under 700 nm.

Including transient effects increases the estimated cut-off frequency from 261 GHz to 663 GHz at 100 nm scale.

All key transport parameters are rigorously extracted and characterized.

Abstract

High electron mobility transistors (HEMT) built using In\textsubscript{0.52}Al\textsubscript{0.48}As/In\textsubscript{0.53}Ga\textsubscript{0.47}As on InP substrates are a focus of considerable experimental studies due to their favourable performance for microwave, optical and digital applications. We present a detailed and comprehensive study of steady state and transient electronic transport in In\textsubscript{0.52}Al\textsubscript{0.48}As with the three valley model using the semi-classical ensemble Monte Carlo method and including all important scattering mechanisms. All electronic transport parameters such drift velocity, valley occupation, average electron energy, ionization coefficient and generation rate, electron effective mass, diffusion coefficient, energy and momentum relaxation time are extracted rigorously from the simulations. Using these, we present a complete characterization of the transient electronic transport showing the variation of drift velocity with distance and time. We have then estimated the optimal cut-off frequencies for various device lengths via the velocity overshoot effect. Our analysis shows that for device lengths shorter than $700$ nm, transient effects are significant and should be taken into account for optimal device designs. As a critical example, at length scales of around $100$ nm, we obtain a significant improvement in the cut-off frequency from $261$ GHz to $663$ GHz with the inclusion of transient effects. The field dependence of all extracted parameters here can prove to be helpful for further device analysis and design.