INFLUENCE OF MOVPE GROWTH-CONDITIONS AND CCL4 ADDITION ON INP CRYSTAL SHAPES

Growth of InP with metalorganic vapour phase epitaxy (MOVPE) around reactive ion etched stripe mesas has been studied. The mesas were oriented along the [110] and [110BAR] directions. Marker layers of different doping were introduced in order to follow growth with respect to time. The growth parameters were varied in order to investigate the influence of reactor pressure, V/III ratio, substrate temperature and addition of CCl4 on the overall growth behaviour. The final crystal shape could, in general, be well described in Wulff diagrams. The results are discussed with respect to diffusion, chemical reactions and surface kinetic aspects. The significant improvement of regrowth properties observed when CCl4 was added is most probably due to Cl adsorption to group V sites, acting as an inhibitor for P adsorption and hence restricting growth on {111} planes. With CCl4 present, the reactor pressure and V/III ratio could be used to further control growth on the {111}A and {110} planes. Due to the asymmetry between {110} and {110BAR} planes, the growth habit was found to be sensitive to the slope of the mesa walls. However, the effect of this sensitivity was diminished when adding Cl.