On the nucleation and composition analysis of InAs1-xPx during vapour phase epitaxial growth

The present investigation deals with the nucleation and growth kinetics of InAs1-xPx vapour phase epitaxy in In-HCl-AsH3-PH3-H-2 systems. The expressions for the critical nucleation parameters are evaluated as a function of surface tension, supercooling and the composition of the alloy and it is found that the (100) orientation has the highest critical nucleation barriers. The expression for the layer composition has been derived in terms of growth rates of InP and InAs, which in turn derived in terms of partial pressures and deposition temperature. The influence of the input gas mole ratio (PH3/(PH3 + AsH3)) and the deposition temperature on the layer composition has been investigated in detail. it is found that the composition is more strongly affected by the gas mole ratio than the deposition temperature, and As is more preferentially deposited than P. Our theoretical findings are compared with the experimental reports and there is a good agreement between them.