Akademik Veri Yönetim Sistemi
MATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS, cilt.323, 2026 (SCI-Expanded, Scopus)
In this study, AlN films with three different Si flow rates were grown on sapphire substrate by Metal Organic Vapor Phase Epitaxy (MOVPE) and then devices were produced by lithography process. According to SIMS results, Si concentrations were obtained as 2 x 1017 cm-3, 8 x 1017 cm-3 and 2 x 1018 cm-3. In addition, the oxygen concentration was also determined from SIMS measurements, and it was shown that the sample with the highest Si doping level had the least step-like behaviour at the interface of the UID-AlN and n-AlN layers. Dislocation densities were calculated using the full-width at half-maximum (FWHM) values of X-ray diffraction (XRD) w (0 0 2) and w (1 0 2) scans. Additionally, peak separation was observed in the XRD w-20 scan of the sample exhibiting the highest dislocation density. The AFM measurements revealed stepped and terraced structures at the lowest Si doping level, while the increase in Si doping level resulted in the formation of irregular and non-parallel large grain structures. The Raman spectra showed that the highest Si doping rate changed the stress type and the E2 (high) phonon peak caused the highest FWHM value. Transmittance spectra of AlN films shown that the absorption edge shifts to lower energies as the Si doping increases. Additionally, the sample with the highest Si doping level has the highest transmittance. I-V measurements at 400, 500 and 550 degrees C exhibit Schottky diode-like properties as the temperature increases. The ideality factor (n) and Schottky barrier height (en) were extracted from the forward bias I-V characteristics based on the thermionic emission model. The doping process applied to the AlN layer is expected to activate Si dopants when subjected to high temperatures.