Prevention of In droplets formation by HCl addition during metal organic vapor phase epitaxy of InN

The low decomposition temperature of InN and relatively high thermal stability of NH3 necessitate the use of a high NH3/TMIn ratio to prevent In droplet formation on the surface. This work shows that the addition of Cl in the form of HCl (Cl/In molar ratio range of 0.3-1.4) to the growth chamber allows the growth of high quality InN films without the formation of a second In phase at a very low value of the N/In molar inlet ratio (2500). Photoluminescence spectra in the temperature range of 144 to 4.5 K showed a broad spectral band with a cutoff energy close to the reported minimum of the InN band gap energy (0.65 eV). (c) 2007 American Institute of Physics.