2024/08/13 by Dylan Wright, Dinusha Herath Mudiyanselage, Wright, Dylan +14
Engineering · Physics and Astronomy · #Acoustic Wave Resonator Technologies #FOS: Physical sciences #GaN-based semiconductor devices and materials #Materials Science (cond-mat.mtrl-sci) #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Ultrasonics and Acoustic Wave Propagation
paper · pdf · doi:10.48550/arxiv.2408.06951
openalex publication_date 2024/08/13 · openalex created_date 2024/09/11 · openalex updated_date 2026/08/01
We report the results of the study of the acoustic and optical phonons in Si-doped AlN thin films grown by metalorganic chemical vapor deposition on sapphire substrates. The Brillouin - Mandelstam and Raman light scattering spectroscopies were used to measure the acoustic and optical phonon frequencies close to the Brillouin zone center. The optical phonon frequencies reveal non-monotonic changes, reflective of the variations in the thin-film strain and dislocation densities with the addition of Si dopant atoms. The acoustic phonon velocity decreases monotonically with increasing Si dopant concentration, reducing by ~300 m/s at the doping level of 3 x 1019 1/cm3. Knowledge of the acoustic phonon velocities can be used to optimize ultra-wide bandgap semiconductor heterostructures and minimize the thermal boundary resistance of high-power devices.