EVALUATION OF COMPOSITION AND GROWTH-RATE OF GAXIN1-XP VAPOR-PHASE EPITAXY

A model has been developed successfully to study the nucleation and gr owth mechanisms of the GaxIn1-xP vapour phase epitaxial (VPE) growth i n the Ga-In-HCl-PH3-H-2 system. Using classical heterogeneous nucleati on theory the critical nucleation parameters have been derived and the effect of substrate orientations has been studied. By applying physic o-chemical concepts, an expression for the composition has been derive d as a function of experimental input parameters by considering the nu mber of intermediate reactions. The effect of experimental input param eters on the nucleation and growth mechanism has been analysed in deta il and it was found that the (100) orientation has the highest nucleat ion barrier, and the composition was strongly affected by deposition t emperature and input gas mole ratio. It was also found that Ga is pref erentially deposited rather than In. The predicted results are compare d with the experimental data and found to be in good agreement.