Mechanism that Dictates Pore Width and <111>A Pore Propagation in InP

We report a mechanism for pore growth and propagation based on a three-step charge transfer model. The study is supported by electron microscopy analysis of highly doped n-InP samples anodised in aqueous KOH. The model and experimental data are used to explain propagation of pores of characteristic diameter preferentially along the <111>A directions. We also show evidence for deviation of pore growth from the <111>A directions and explain why such deviations should occur. The model is selfconsistent and predicts how carrier concentration affects the internal dimensions of the porous structures.