Growth mode and effect of carrier gas on In Ga AsrInP 0.53 0.47 surface morphology grown with trimethylarsine and arsine

Different growth mode have been observed for InGaAsrInP grown with trimethylarsine and arsine by Metalorganic Vapor Phase Epitaxy MOVPE.when changing the carrier gas. The surface has been investigated by Atomic Force Microscope AFM.for epilayers grown at 6008C under pure hydrogen or a mixture of hydrogen and nitrogen as carrier gas. The steprterrace surface morphology was observed for InPrInP and InGaAsrInP 001. using 0.28 off substrates. InP epilayers grown under nitrogen flow show step-bunched terraces as large as 170 nm. The effect of the group V source for InGaAsrInP has been studied. It is shown that the step edge characteristic of step flow growth appears for lattice-matched InGaAsrInP grown with arsine. When using TMAs and hydrogen as a carrier gas, the growth mode and surface roughness depends greatly on VrIII ratio and growth temperature. Under nitrogen flow with the combination of TMIqTMGqTMAs, pit-like defects 5–8 nm deep.are visible at high surface concentration 109–1010rcm2.. When increasing VrIII ratio, 3D growth occurs simultaneously with pit-like defects, recovering the whole surface of the sample. Various surface morphology characteristics of InGaAs epilayers assessed by AFM characterisation will be presented and discussed. q1999 Elsevier Science B.V. All rights reserved.