GROWTH OF INP IN A NOVEL REMOTE-PLASMA MOCVD APPARATUS - AN APPROACH TO IMPROVE PROCESS AND MATERIAL PROPERTIES

Remote plasma metalorganic chemical vapor deposition (RP-MOCVD) technique, though relatively new, is becoming more and more important in the processing of the III-V semiconductor materials and, specifically, of indium phosphide. So far different processes have been designed for (a) the cleaning of InP substrates to remove surface native oxide by reduction with H-2 plasma and (b) the InP deposition under PH3 plasma preactivation. This paper deals with InP homoepitaxial growth by trimethylindium (TMI) and plasma preactivated PH3. Optical emission spectroscopy (OES) measurements evidence the presence of PH and PH2 radicals, and of H-atoms in the plasma phase. Mass spectrometry (MS) sampling close to the growth surface reveals the presence of alchylphosphine ((CH3)(2)PH, CH3PH2), indium-phosphorus adduct and biphosphine (P2H4), whose relative amounts depend on the growth conditions. Stoichiometric InP epilayers having good structure and morphology, and with a very high photoluminescence intensity are prepared under PH3 plasma preactivation, even at very low V/III ratio (=20) and reduced temperature (similar to 550 degrees C).