Impact of Deep-Level Traps on Carrier Mobility in β-Ga2O3 MOSFETs

Published

April 7, 2026

Author(s)

Ory Maimon, Neil Moser, Pragya Shrestha, Minyeong Kim, Sang-Mo Koo, Kyle Liddy, Andrew Green, Kelson Chabak, Sujitra Pookpanratana, Qiliang Li

Abstract

Ultra-wide bandgap β-Ga2O3-based power devices are promising and rapidly developing, but its mobility in field-effect transistors (FET) falls short of the theoretical value. An electro-optical measurement technique is used to study ionized impurity scattering by deep-level traps in lateral depletion-mode β-Ga2O3 FETs. Using the conductance method and photo-assisted capacitance-voltage (PCV) measurements with sub-bandgap illumination from 730 nm (1.7 eV) to 280 nm (4.4 eV), the interface trap state density, Dit, is found from 0.4 eV – 4.4 eV below conduction band, EC. Dit peaks near the band edges, similar to conventional material systems. The dark and post-illumination effective mobility is then calculated using the mobile charge density from PCV and drain conductance from a similar photo-assisted current-voltage (PIV) measurement. Based on the results, traps located between EC – 4.0 eV and EC – 3.4 eV are primarily responsible for carrier scattering, reducing the mobility by 12 % – 28 % in these devices with increasing distance from the interface. The increased mobility degradation further from the interface is attributed to traps located in the bulk.

Citation

IEEE Transactions on Electron Devices

Volume

73

Issue

5

Pub Type

Journals

Download Paper

https://doi.org/10.1109/TED.2026.3678479

Local Download

Keywords

power electronics, semiconductors, defects, ultrawide bandgap semiconductors

Citation

Maimon, O. , Moser, N. , Shrestha, P. , Kim, M. , Koo, S. , Liddy, K. , Green, A. , Chabak, K. , Pookpanratana, S. and Li, Q. (2026), Impact of Deep-Level Traps on Carrier Mobility in β-Ga2O3 MOSFETs, IEEE Transactions on Electron Devices, [online], https://doi.org/10.1109/TED.2026.3678479, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=959460 (Accessed April 29, 2026)

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