AUTOMATION OF GROWTH RATE MEASUREMENTS FOR ALN/GAN HETEROEPITAXIAL STRUCTURES WITH A TWO-DIMENSIONAL ELECTRON GAS, GROWN USING AMMONIA MOLECULAR BEAM EPITAXY
I.N. Lyapustin1,2, V.G. Mansurov1, T.V. Malin1, A.M. Gilinsky1, Ya.E. Maidebura1, V.I. Vdovin1, Yu.A. Zhivodkov1, D.S. Milakhin1,3
1Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
2Novosibirsk State University, Novosibirsk, Russia
3Novosibirsk State Technical University, Novosibirsk, Russia
Keywords: III-nitrides, ammonia MBE, AlGaN/AlN/GaN heterostructures, growth rate, FFT filtering
Abstract
A method compatible with the growth process has been proposed for processing reflectograms recorded in situ by a laser reflectometer during the growth of III-nitride layers by ammonia molecular beam epitaxy. This method includes data filtering based on the fast Fourier transform. The cause of an additional high-frequency signal appearing and interfering with the registration of informative interference oscillations of reflected light intensity has been established as the oscillation of the holder with the sample installed on it during growth rotation. Sample rotation is a necessary technological technique in molecular beam epitaxy growth, ensuring increased uniformity of epitaxial film parameters. A comparison of the thickness values of individual III-nitride layers, as determined by the processing of reflectograms using software, with values determined by scanning electron microscopy demonstrates good agreement between the two methods. Software has been developed that automatically filters out high-frequency signals and determines the growth rate of individual III-nitride layers grown by ammonia molecular beam epitaxy.
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