Depth-resolved analysis of spontaneous phase separation in the growth of lattice-matched AlInN

A Redondo-Cubero (1, 2) , K Lorenz (3) , R Gago (4) , N Franco (3) , M.-A Di Forte Poisson (5) , E Alves (3) , E Muñoz (1)

1 ISOM and Dpt. de Ingeniería Electrónica
2 Centro de Micro-Análisis de Materiales
3 Instituto Tecnológico e Nuclear
4 ICMM - Instituto de Ciencia de Materiales de Madrid
5 Thales Research & Technology / TIGER

We report the detection of phase separation of an Al 1-x In x N/GaN heterojunction grown close to lattice matched conditions (x∼0.18) by means of Rutherford backscattering spectrometry in channeling geometry and high resolution x-ray diffraction. An initial pseudomorphic growth of the film was found, with good single crystalline quality, the nominal composition and very low strain state. After ~50 nm, a critical thickness is reached at which the InN molar fraction of the films drops to ~15 % and at the same time the single crystalline quality of the films degrade drastically. This spontaneous effect cannot be ascribed to strain relaxation mechanisms since both techniques show a good single crystalline growth of the ternary under lattice matched conditions.

Mots clés: RBS; channeling; AlInN; strain; XRD

A Redondo-Cubero, K Lorenz, R Gago, N Franco, M.-A Di Forte Poisson, et al.. Depth-resolved analysis of spontaneous phase separation in the growth of lattice-matched AlInN. Journal of Physics D: Applied Physics, 2010, 43 (5), pp.55406. ⟨10.1088/0022-3727/43/5/055406⟩. ⟨hal-00569755⟩