Composition control of GaSbAs alloys

We report on a detailed study on the dependence of GaSbxAs1-x alloy composi tion (x < 0.5) on the fluxes of the individual constituents Ga. Sb and As. The values of fluxes are obtained by the analysis of RHEED oscillations und er Ga-, As- and Sb-limited growth conditions, while the alloy composition h as bt en derived by the combined use of photoluminescence and Rutherford ba ckscattering spectrometry measurements. It is shown that the Sb mole fracti on: (i) increases with increasing Ga flux when the other parameters are kep t constant, (ii) increases with increasing Sb flux and, (iii) for given Ga and Sb fluxes, is basically independent of the As Bur for relatively high A s fluxes, while it increases as the As fluxes are reduced. The present resu lts allow an improved control of composition of the GaSbAs alloys that are considered of increasing interest For optoelectronic applications. (C) 1999 Published by Elsevier Science B.V. All rights reserved.