Systematic study of the surface morphology of ordered GaIn/P

The surface morphology of CuPtB-type ordered GaIn.P, lattice-matched grown on 001.GaAs by low-pressure MOVPE, was systematically investigated by means of atomic force microscopy. Since surface steps, e.g. provided by different misorientations of the substrates, are known to affect the ordering behaviour, the superstep distances and heights are examined in order to correlate the surface structure to the existing ordering. In order to correlate both surface morphology and ordering, experiments have been performed varying the growth parameters and the partial pressure of the phosphorous precursors phosphine PH3., tertiarybutylphosphine TBP.and ditertiarybutylphosphine DitBuPH., and finally the Zn doping concentration. From these results, in addition to previously reported data wS.H. Lee, G.B. Stringfellow, J. Appl. Phys. 83 1998.3620x, generally valid dependencies for the superstep distances, superstep heights, and the degree of ordering are derived and interpreted. q2000 Elsevier Science B.V. All rights reserved.