INTERDIFFUSION OF THE GROUP-III SUBLATTICE IN IN-GA-AS-P IN-GA-AS-P AND IN-GA-AS IN-GA-AS HETEROSTRUCTURES

We present the results of a photoluminescence study of interdiffusion on the group-III sublattice in the ternary In-Ga-As/In-Ga-As and the quaternary In-Ga-As-P/In-Ga-As-P systems, both grown off InP substrates. We have shown that the diffusion obeys Fick's law, and that over the temperature range 950 degrees C-650 degrees C, the diffusion coefficients of both the ternary and quaternary materials can be described by the equation D = D(0)exp(-E(A)/kT), where E(A) = 3.4 +/- 0.2 eV and D-0 = 3.9 cm(2)/s. Within experimental error these values are identical to those previously measured for interdiffusion on the group V in the same material system.