Growth of Fe Islands on Clean and Ammonia-saturated Si(111)7 x 7 Surfaces Studied by in situ Electron Diffraction

We investigated the epitaxial growth of Fe islands on clean and ammonia-saturated Si(111)7 x 7 surfaces by reflection high-energy electron diffraction for 0-10 monolayer Fe coverage. From the profile analyses of transmission electron diffraction spots of Fe crystalline islands, we found that the islands grew at a lower speed, with a larger and a smaller height on the ammonia-saturated surfaces indicating a weak three-dimensional (3D) island feature than that on the clean surfaces indicating a strong 3D feature. The difference in the Fe growth was ascribed to the density of nucleation centers because half of the reactive bare Si adatoms were inactivated on the ammonia-saturated surfaces. From the analyses of the crystalline domain size and relative number of domains at the initial growth stage on both surfaces, we suggested Fe configuration models that initiate the nucleation centers.

Automated summary

This study investigated the epitaxial growth of Fe islands on clean and ammonia-saturated Si surfaces, revealing that ammonia-saturated surfaces resulted in slower growth rates and weaker 3D island features for Fe islands. The difference was attributed to a lower density of nucleation centers on ammonia-saturated surfaces due to inactivation of half of the reactive bare Si adatoms. Analysis of crystalline domain size and relative number of domains at the initial growth stage suggested Fe configuration models that initiate the nucleation centers.