12.2 – Crystallographic Dependency of β-Ga2O3 Nitridation via RF Nitrogen Plasma for GaN Heteroepitaxy

J. I. Stavehaug, University of Illinois at Urbana-Champaign,
G. R. Czajkowski, University of Illinois at Urbana-Champaign
Matthew Landi, University of Illinois at Urbana-Champaign
Frank Kelly, University of Illinois at Urbana-Champaign
K. Kim, University of Illinois at Urbana-Champaign

12.2 Final.2025

Abstract
RF-plasma assisted nitridation was used to transform (100) -Ga2O3 to (0001) wurtzite GaN and subsequently grow a 520 nm p-GaN cap layer over 5 intervals. The final step involved a 11.5 hour anneal at the growth temperature of 680 C to allow for equilibration inside the crystal body. The nitridated film was characterized via X-ray diffraction (XRD), which revealed peaks distinct from the (0001) family. Analysis of these distinct peaks revealed varying (𝒉𝟎𝒍) orientations. We theorize that the alternate orientations are forming to accommodate the growing GaN film, gradually shifting towards the ideal heteroepitaxy plane of (𝟐̅𝟎𝟏). XRD rocking curves of the (0002) GaN were used to analyze crystallinity as a function of thickness. Results showed a transformation at the 120 nm interval, from a single Gaussian-like peak to a broad-narrow dual peak configuration. The FWHM’s were extracted and plotted against a previous study, indicating narrower, improved peak of 20%.