XXVI International Symposium "Nanophysics and Nanoelectronics", Nizhny Novgorod, March 14 - March 17, 2022

Determination of the AlN nucleation layer thickness formed on the Al$_2$O$_3$ (0001) surface during nitridation process by XPS and IR spectroscopy

D. S. Milakhin^ab, T. V. Malin^a, V. G. Mansurov^a, A. S. Kozhukhov^a, N. N. Novikova^c, V. A. Yakovlev^c, K. S. Zhuravlev<sup>a

a</sup> Rzhanov Institute of Semiconductor Physics, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia
^b Novosibirsk State Technical University, 630073 Novosibirsk, Russia
^c Institute of Spectroscopy, Russian Academy of Sciences, 108840 Troitsk, Moscow, Russia

Abstract: The effect of different degrees of the sapphire surface nitridation process completion on the AlN buffer layer morphology has been studied. It was found that $\sim$85% completion of the AlN crystalline phase formation promotes the growth of a two dimensional AlN buffer layer with a smooth surface morphology, regardless of the substrate temperature and ammonia flux. In contrast, during the AlN nucleation layer formation as a result of weak or excessive sapphire nitridation, a polycrystalline or three-dimensional AlN structures with a high density of inversion domains, respectively, were formed. Using independent methods of X-ray photoelectron spectroscopy and infrared spectroscopy of surface polaritons, the thickness of the AlN nucleation layer was determined at $\sim$85% degree of the nitridation process completion, which amounted to $\sim$1 monolayer.

Keywords: ammonia molecular beam epitaxy, AlN, sapphire, reflection high-energy electron diffraction, nitridation, inversion domains, X-ray photoelectron spectroscopy, surface polaritons.

Received: 02.03.2022
Revised: 25.03.2022
Accepted: 25.03.2022

DOI: 10.21883/FTP.2022.08.53137.23

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