Growth of thick InGaN films with entire alloy composition using droplet elimination by radical-beam irradiation

•This paper reports on the new growth technique of thick InGaN films with entire alloy composition.•No precise control of In beam supplied flux is needed during growth in this method.•High-quality thick and uniform InGaN films were successfully and reproducibly fabricated.

Droplet elimination by radical-beam irradiation (DERI), which is suitable for the growth of InN and periodic InN/InGaN structures, was developed for the growth of thick InGaN films by radio-frequency plasma-assisted molecular beam epitaxy (RF-MBE). In this method, Ga-to-nitrogen radical (N) beam flux ratio was fixed in the entire growth process, and In beam supply was modulated under the condition in which excess In of more than 2–3 monolayer wetting layers always existed on the surface, that is, no precise control of In beam flux during growth was needed. Thick and uniform InGaN films were successfully grown by the developed method. In addition, InGaN films with an entire alloy composition could be simply grown by controlling Ga-to-N beam flux ratio.