Growth Morphology of Vicinal Hillocks on the {101} Face of KH2PO4: From Step-Flow to Layer-by-Layer Growth

The growth morphologies of vicinal hillocks on K${\mathrm{H}}_2$P${\mathrm{O}}_4$ {101} surfaces have been investigated using atomic force microscopy. Growth occurs on monomolecular steps both by step-flow and through layer-by-layer growth on both dislocation induced steps and 2D nuclei. Dislocation induced hillocks exhibit hollow cores. The circular cross sections of these cores are consistent with an isotropic step edge energy and the core radii are in good agreement with theoretical predictions. From the interisland spacing we estimate the surface diffusion length to be 200 to 300 nm at 300 K.