In situ Al2O3 atomic layer deposition on pristine (0 0 1) GaAs: interface chemistry and its implication on charge carrier recombination and Fermi level pinning
Published 6 November, 2025
In a recent collaboration with PGI-2, researchers have achieved a significant advance in understanding the Al₂O₃/GaAs interface formed by in situ atomic layer deposition. The study demonstrated a reduction of band bending by 0.2–0.4 eV, indicating a lower interface state density and a partial unpinning of the Fermi level at the interface.
This breakthrough is crucial for the development of high-performance III/V semiconductor devices, as it enhances gate control and reduces electronic noise. The findings open new possibilities for high-frequency, low-noise electronics and optoelectronic applications in fields such as wireless communication, AI hardware, and clean energy technologies.
Abstract: Al2O3/GaAs interface formed by in situ atomic layer deposition of Al2O3 on (0 0 1) GaAs. The reduction of band bending in GaAs at the Al2O3/GaAs interface by 0.2–0.4 eV indicating a decrease in interface state density, i.e. the unpinned state of the Fermi level at the interface. This finding is of outmost technological relevance, since a high density of interface states fixes the Fermi level position at the interface (Fermi level pinning) preventing its modulation by the external electric field and thus degrading the gate control of the channel charge. To overcome this problem has impact in the performance of many high-end devices fabricated from III/V compounds, like high frequency devices offering low noise and low thermal sensitivity as well as of optoelectronic devices for applications in solid-state electronics, wireless communication, artificial intelligence, clean energy generation.
Autors: Nataliya Demarina, Soraya Karimzadah, Benjamin Bennemann, Christoph Krause, Abdur Rehman Jalil, Heinrich Hartmann, Beata Kardynał, Mihail Ion Lepsa, Detlev Gruetzmacher
Journal: Applied Surface Science, Volume 720, Part A, 2026, 165114, ISSN 0169-4332
DOI: https://doi.org/10.1016/j.apsusc.2025.165114
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Last Modified: 10.11.2025