Plasma-Assisted Halide Vapor Phase Epitaxy for Low Temperature Growth of III-Nitrides

Abstract

Developing growth techniques for the manufacture of wide band gap III-nitrides semiconductors is important for the further improvement of optoelectronic applications. A plasma-assisted halide phase vapor epitaxy (PA-HVPE) approach is demonstrated for the manufacture of undoped and In-doped GaN layers at ~600 °C. A dielectric barrier discharge (DBD) plasma source is utilized for the low-temperature activation of ammonia. The use of the plasma source at a growth temperature of ~600 °C increases the growth rate from ~1.2 to ~4–5 µm/h. Furthermore, the possibility for the growth of InGaN at ~600 °C has been studied. Precursors of GaCl and InCl/InCl3 are formed in situ in the reactor by flowing HCl gas over a melt of metallic Ga and In, respectively. The In concentration was low, in the order of a few percent, as the incorporation of In is reduced by plasma due to the activation of chlorine-containing species that etch the relatively poorly bonded In atoms. Nevertheless, the approach of using plasma for ammonia activation is a very promising approach to growing epitaxial III-nitrides at low temperatures.