We correlated In-incorporation with residual strain/relaxation in InAlN layers. In-rich InAlN is needed as a buffer for InN channel transistors. Growths directly on sapphire or on GaN/sapphire template were tested. In comparison to later one, full relaxation in InAlN grown on sapphire was observed. Consequently, an increase of the In-molar fraction from 0.28 to 0.60, if compared with the GaN template was obtained.
a) Representative XRD 2θ/ω scan of In0.60Al0.40N grown on (0001) sapphire, b) Negative Cs HRTEM image of InxAl1-xN layer of sample grown on sapphire showing aligned columns of N atoms (blue) and In/Al atoms (red), c) In, N, Al, O and C elemental depth profiles in InxAl1-xN layers along the growth direction [0001].
Chauhan, P., Hasenöhrl, S., Dobročka, E., Chauvat, M.-P., Minj, A., Gucmann, F., Vančo, Ľ., Kováč, J.jr., Kret, S., Ruterana, P., Kuball, M., Šiffalovič, P., and Kuzmík, J.: Evidence of relationship between strain and In-incorporation: growth of N-polar In-rich InAlN buffer layer by OMCVD, J. Applied Phys. 125 (2019).
Chauhan, P., Hasenöhrl, S., Minj, A., Chauvat, M.P., Ruterana, P., and Kuzmík, J, Growth evolution of N-polar Indium-rich InAlN layer on c-sapphire via strain relaxation by ultrathin AlON interlayer, Applied Surface Sci 502 (2020) 144086.
Chauhan, P., Hasenöhrl, S., Dobročka, E., Vančo Ľ., Stoklas, R., Kováč, J., Šiffalovič, P., and Kuzmík, J.: Effect of temperature and carrier gas on the properties of thick InxAl1-xN layer, Applied Surface Sci 470 (2019) 1-7.
Hasenöhrl, S., Chauhan, P., Dobročka, E., Stoklas, R., Vančo, Ľ., Veselý, M., Bouazzaoui, F., Chauvat, M.-P., Reterana, P., and Kuzmík, J.: Generation of hole gas in non-inverted InAl(Ga)N/GaN heterostructures, Applied Phys. Express 12 (2019) 014001.