Zinc diffusion enhanced Ga diffusion in GaAs isotope heterostructures

We have investigated the simultaneous diffusion of Zn and Ga in a (69)GaAS/(71)GaAs isotope multilayer structure at temperatures between 618degreesC and 714degreesC. Diffusion profiles of Zn, (69)Ga, and (71)Ga were measured with secondary ion mass spectrometry. Accurate modeling of the simultaneous diffusion of Zn and Ga is achieved on the basis of a Ga vacancy and Ga interstitial controlled mode of Zn diffusion. This result is at variance with the generally accepted model of Zn diffusion via Ga self-interstitials. We discuss the consequences of our approach against the background of Zn and Cd diffusion experiments performed earlier. (C) 2001 Elsevier Science B.V. All rights reserved.