| dc.description.abstract | High crystalline and optical quality aluminum nitride (AlN) films with thin
thickness have been grown on Al2O3 by MOVPE (metal-organic vapor phase
epitaxy) and the NH3 flow rate has been changed to improve the morphology
and quality of the films. Some characterization types of equipment such as
atomic force microscopy (AFM), high-resolution X-ray diffraction (HRXRD),
and Raman spectroscopy have been carried out to investigate the effect of different
NH3 flow rates on surface morphology, roughness, and crystal quality of
AlN, respectively. Unlike in the literature, in situ optical reflectance measurements
have been given depending on NH3 flow rate and optical characterization
has been performed by UV–VIS–NIR spectrophotometry. The well-defined
interference patterns in the optical transmittance graph report a sharp interface
between AlN and Al2O3. Also, all obtained samples have a sharp absorption
edge that shows the quality of the films, but Sample B with 900 sccm NH3 flow
has the sharpest absorption edge because it has high optical quality and low
defect. The RMS (root mean square), DS (screw-type dislocation density), and
DE (edge-type dislocation density) values of AlN with 900 sccm NH3 flow are
0.22 nm, 7.86 [ 107 , and 1.68 [ 1010 cm-2, respectively. The results obtained are
comparable to the literature. | tr |
