Plasma-assisted molecular beam epitaxy growth and properties of indium-face indium nitride

In this work, the PAMBE growth of high-quality InN films was developed. Using the in situ growth analysis tools, RHEED and line-of-site quadrupole mass spectrometry (QMS), the thermal decomposition of both Inand N-face InN was explored to determine attainable growth temperatures and growth rate limitations. Surface structure growth diagrams were constructed for both In- and N-face InN. In-face InN was shown to have only two growth regimes below 500ºC--the In-droplet regime and the N-rich regime. Attempts to grow beyond 500ºC resulted in In-droplet accumulation with no InN growth. Both In- and N-face InN exhibited the smoothest surface morphologies and lowest dislocation densities for films grown with excess In.;The dependence of electrical transport properties on growth conditions were studied for In-face InN. An accumulation of electrons with a density of 5.1 x 1013 cm-2 was measured at the sample surface due to occupied surface states above the bulk conduction band minimum. This surface accumulation layer interfered with direct Hall measurements of bulk carriers, but a two-layer Hall model was used to extract bulk electron concentrations and mobilities. Even when accounting for this surface accumulation layer, all of the InN films exhibited a degenerate level of unintentionally doped (UID) n-type bulk conductivity. Films grown at the highest substrate temperatures with excess In had the lowest electron concentration and highest electron mobility.;The UID electron concentration was shown to originate from impurity incorporation. A correlation between electron concentration and dislocation density was not observed, but dislocations were shown to limit the electron mobility in the InN films. The control of n-type conductivity in InN was demonstrated using a combination of Si-doping, variable growth temperature, and Mg-doping. The electron concentrations were controlled over a range of three orders of magnitude, with Mg-doped films demonstrating bulk electron concentrations as low as 3 x 1016 cm-3 and Si-doped films with electron concentrations as high as 3 x 1019 cm -3.