Growth mechanism of vertical compositional inhomogeneities in AlInN films

Abstract

The growth mechanisms of vertical compositional inhomogeneities were investigated in lattice-matched AlInN films prepared by metalorganic chemical vapour deposition. X-ray diffraction and secondary ion mass spectrometry measurements demonstrated a fluctuation of the indium (In) atomic fraction at the initial growth stage. Some In droplets formed on the surface of the inhomogeneous AlInN films, when In was excess caused by the initial Al-rich AlInN layer. The compositional inhomogeneities were attributed to the self-assembled In droplets by increasing the surface In content.

Comparative study of intersubband absorption in AlGaN/GaN and AlInN/GaN superlattices: Impact of material inhomogeneities

“…1(a)], suggesting that the alloy composition is laterally inhomogeneous on the scale of a few nanometers. These compositional inhomogeneities have been widely reported in the literature 14,[16][17][18] and are attributed to the large lattice mismatch (13%) between AlN and InN. In the cross-sectional image, the bright (high-In containing) regions can be seen to form columns propagating along the growth direction, while the plan-view images reveal that these columns form a honeycomb nanostructure [ Fig.…”

Contribution of GaN template to the unexpected Ga atoms incorporated into AlInN epilayers grown under an indium-very-rich condition by metalorganic chemical vapor deposition (MOCVD)

“…It is noted that in this study, the AlIn(Ga)N epilayers were grown under an In rich condition, and tiny In droplets are possible to form in the grown layers [18,19]. The In droplet formation and the permeation of In may enhance the dissociation of GaN by lowering the decomposition temperature with In acting as a catalyst [18].…”

Nature and origin of V-defects present in metalorganic vapor phase epitaxy-grown (InxAl1−x)N layers as a function of InN content, layer thickness and growth parameters

“…The presence of composition fluctuations and surface hillocks has been reported [4][5][6][7][8][9]. In MOCVD-grown layers, the most commonly encountered defects are V-pits.…”