Nucleation layer temperature effect on AlN epitaxial layers grown by metalorganic vapour phase epitaxy
Citation
Simsek, I., Yolcu, G., Koçak, M., Pürlü, K., Altuntas, I., & Demir, I. (2021). Nucleation layer temperature effect on AlN epitaxial layers grown by metalorganic vapour phase epitaxy. Journal of Materials Science: Materials in Electronics, 32(20), 25507-25515.Abstract
AlN samples have been grown on sapphire substrate using nucleation layers
(NLs) having different growth temperatures. The growth temperature of the NL
has been varied over a wide range of temperatures highlight the effects on the
quality of the AlN epilayer. The AlN samples have been characterized by highresolution
X-ray diffraction (HRXRD), atomic force microscope (AFM), Raman
scattering spectrometer, and spectrophotometer. The obtained results demonstrate
the temperature of NL has a direct effect on the quality of the AlN sample
and occurs major differences in the quality of structure, surface morphology,
and amount of strain in the AlN epilayers. Based on HRXRD measurement
results, when the growth temperature of AlN NL is raised to 1075 C, the crystal
quality has improved owing to both the density of AlN nucleation islands
reduction and the grain size outgrow. However, continuing to increase the
growth temperature of the AlN NL layer begins to degrade the quality. In
addition, the findings obtained from the Raman measurement demonstrates that
the tensile stress can be control through NL growth temperature. Therefore, as
can be seen from the characterization results, the growth temperature of AlN NL
is important to obtain an AlN sample with high quality.