Indium phosphide vapor phase epitaxy at high growth rates, growth kinetics, and characterization

Abstract

InP epitaxial layers have been grown at high growth rates by vapor phase reactive transport. A systematic study of the influence of growth conditions on the growth rate, surface morphology, and photoluminescence properties of the grown materials has been performed. The results show that the growth rate can be controlled at least between 0.3 and 75 μm per hour, the latter being over 75 times of the growth rate obtained with the usual techniques. The changes of the surface morphology of the layers with the growth conditions have been understood and layers having mirror-like surfaces can be grown for any growth rate. The mass transport mechanism occurs through three chemical reactions whose activation energies have been determined and a reliable model for the growth rate as a function of the growth conditions is now available. Double diffraction x-ray measurements demonstrate that the layers are characterized by a peak whose width at half maximum is 18 arcsec, even for the highest growth rates. Low temperature luminescence exhibits transitions involving free and bound excitons, and shallow donors and acceptors. C and Zn are identified as the only residual acceptors and no radiative deep levels are detected. Depending on the growth conditions, C or Zn are incorporated preferentially as the dominant acceptor. The intensity ratio of the excitonic transition to the transition involving Zn as acceptor varies exponentially with the growth temperature.