Growth of gallium nitride-based nitride semiconductors by PAMBE for development of optoelectronic and microelectronic devices

GaN-based nitride films are prepared under various growth conditions using the plasma assisted molecular beam epitaxy (PAMBE) and the properties of these films are investigated. An analysis of GaN-based nitride films grown under various conditions suggests that the properties of films depend on both the flux ratio between group III and group V and the growth rate.; The flux ratio effect on the properties of undoped GaN films strongly suggest that the growth conditions under high Ga flux promote two-dimensional (2-D) growth, resulting in a smooth surface, excellent crystallinity, and good electrical properties. The decreased growth rate appears to facilitate complete 2-D growth and suppress the generation of dislocations in films. The quality of undoped GaN films with different buffer layer structures is also investigated. The films grown on the high-temperature-AIN buffer layer exhibit better crystallinity, optical and electrical properties, and surface stability than those grown with the nitridation layer, which can be explained by the lattice polarities of films.; The effects of growth rate on the quality of n-type and p-type GaN films are investigated. The decreased growth rate improves the surface morphologies, crystallinity, and electrical properties of films. The generation of Si-doping-induced defects is much suppressed by the decreased growth rate, resulting in a high-optical quality of n-type GaN films. The decreased growth rate also facilitates Mg incorporation into the shallow acceptor level in p-type GaN films, resulting in an increase of hole concentration in the films.; An analysis of InGaN and AlGaN films grown with different flux ratios indicates that the quality of films grown under the group III-rich condition improves due to 2-D growth leading to matching stoichiometry between group III and group V in the films.; Several devices, i.e., homo junction light-emitting diode (HJ LED), multi-quantum well (MQW) LED, and buried gate junction field effect transistor (BGJFET), are fabricated by PAMBE and their characteristics are demonstrated to show the high quality of GaN-based nitride films grown by PAMBE.