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 111-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 H2 plasnla 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 spcctroscopy (OES) measurements evidence the presence of 1'H and pH2 radicals, and of H-atoms in Lhe plasma phase. Mass spectrometry (MS) sampling close to the growth surface reveals the presence of alchylphosphinc ((CH3)2PH, CH3PH2). indium-phosphorus adduct and biphosphine (F2Hq). whose relative amounts depend on the growth conditions. Stoichiometric Id ' epilayers having good structure and morphology. and with a very high photolurninescencc intensity are prepared under PH3 plasma preactivation, even at very low VIIII ratio (=20) and reduced temperalure (-550°C).