Diffusion of oxygen in aluminum nitride

J. Tröger-Neuhaus^1,2, T. Schulz³, C. Hartmann³, T. Remmele³, S. Hagedorn⁴, L. Kirste⁵, B. Hagenhoff², and H. Bracht¹

Published in:

J. Appl. Phys., vol. 139, no. 10, pp. 105105, doi:10.1063/5.0318177 (2026).

Abstract:

In this study, we investigate the thermal diffusion behavior of oxygen in bulk aluminum nitride (AlN) using an aluminum oxide ( Al₂O₃) coating layer as an oxygen source. We used dynamic secondary ion mass spectrometry (D-SIMS) and time-of-flight SIMS (ToF-SIMS) for accurate profiling of the oxygen concentration across the Al₂O₃/AlN interface of as-grown and annealed samples. Initial tailing and limited dynamic range of ToF-SIMS measurements due to oxygen redeposition was addressed by employing an optimized dual-beam sputtering strategy with staged crater resizing. This eliminates all adverse effects and allows achieving detection sensitivity and depth resolution comparable to D-SIMS. Additional artifacts in the chemical profiling arise from surface roughening and localized phase transitions from amorphous Al₂O₃ to partially crystalline Al_xO_y induced by the high-temperature annealing, which are supported by correlative AFM (atomic force microscopy) and TEM (transmission electron microscopy) analyses. Eliminating all these factors reveals that, upon high-temperature annealing, a limited thermal diffusion of oxygen into AlN occurs after 12 h at 1600 °C, or after 4 and 1 h at 1700 °C, respectively, indicating an oxygen diffusion coefficient below 1.8 × 10¹⁶ cm² s^-1 under these conditions.

Topics:

Diffusion coefficient, Phase transitions, Atomic force microscopy, Sputter deposition, Transmission electron microscopy, Nitrides, Secondary ion mass spectrometry

© 2026 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/)
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