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) techni que, 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 re duction with H-2 plasma and (b) the InP deposition under PH3 plasma pr eactivation. This paper deals with InP homoepitaxial growth by trimeth ylindium (TMI) and plasma preactivated PH3. Optical emission spectrosc opy (OES) measurements evidence the presence of PH and PH2 radicals, a nd of H-atoms in the plasma phase. Mass spectrometry (MS) sampling clo se to the growth surface reveals the presence of alchylphosphine ((CH3 )(2)PH, CH3PH2), indium-phosphorus adduct and biphosphine (P2H4), whos e 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 preactivatio n, even at very low V/III ratio (=20) and reduced temperature (similar to 550 degrees C).