EFFECTS OF GROUP-V PRECURSOR AND STEP STRUCTURE ON ORDERING IN GAINP

The effects of the P precursor have been studied for GaInP layers grow n at 670 degrees C on singular (001) GaAs substrates. Use of either of the two precursors, tertiarybutylphosphine (TBP) and phosphine (PH3), for the organometallic vapor phase epitaxial growth, has been shown t o result in the same degree of CuPt order in the epitaxial layers, How ever, the steps on the surface are mainly bilayers, approximately 5.8 Angstrom in height, for growth using TBP and mainly monolayers for gro wth using PH3. This indicates that the step structure plays no role in the ordering process occurring on the surface during growth. Examinat ion of the spacing between these surface steps vs the input partial pr essure of the P precursor indicates that neither the surface diffusion coefficient nor the sticking coefficients of group III adatoms at the step edge is dependent on the P precursor. This suggests that the ste p structure also has no effect on the sticking coefficient.