Impurity diffusion enhancement of interdiffusion in an InGaPAs-GaAs heterostructure

Publisher Website
Google Scholar
Abstract
The influence of concurrent diffusion of Zn and Si on the interdiffusion on the cation and anion sublattices was studied in InxGa1−xPyAs1−y-GaAs heterostructures (with x and y≊0.05). The heterostructures are grown by liquid phase epitaxy and the diffusion sources are equilibrium ternary tie triangle sources. The extent of interdiffusion on both group III and V atoms is observed by depth profiling In and P, respectively, with secondary ion-mass spectrometry. The Zn diffusion selectively enhances the cation (In-Ga) interdiffusion, whereas Si diffusion enhances both cation and anion interdiffusion to the same extent. A kick-out mechanism is proposed to explain the selective enhancement of the cation interdiffusion induced by Zn, and a single vacancy mechanism is proposed for the interdiffusion due to Si. Based on those observations, we propose that the impurity diffusion mechanism is a major factor in determining the degree of enhancement.