Self-Assembled Lanthanum Gallate Microdots and Holes on Si

Doped lanthanum gallate thin films deposited on Si(111) substrates by radio frequency (RF)-sputtering reveal the presence of self-assembled islands that are of the order of microns in size. These microdots are accompanied by slightly larger holes which form part of the same overall arrangement as the microdots. We present the results of our scanning electron microscope (SEM) and energy dispersive spectrometry (EDS) investigations of these microdots. The formation of the microdots is compared to that of quantum dots (QDs) on semiconductor surfaces, and a model is proposed for the formation process of the microdots and the holes by analogy with the nucleation and growth of islands at the nano-scale