Modeling of Threading Dislocation Density Reduction in Porous III-Nitride Layers

In this work, we report on the results of the theoretical analysis of threading dislocation (TD) density reduction in porous III-nitride layers grown in polar orientation. The reaction-kinetics model originally developed for describing TD evolution in growing bulk layers has been expanded to the case of the porous layer. The developed model takes into account TD inclinations under the influence of the pores as well as trapping TDs into the pores. It is demonstrated that both these factors increase the probability of dislocation reactions thus reducing the total density of TDs. The mean pore diameter acts as an effective interaction radius for the reactions among TDs. The model includes the main experimentally observed features of TD evolution in porous III-nitride layers.