Islanding, growth mode and ordering in Si heteroepitaxy on Ge(001) substrates structured by thermal annealing
arXiv:1902.01207 · doi:10.1016/j.susc.2019.02.002
Abstract
Si/Ge heteroepitaxial dots under tensile strain are grown on nanostructured Ge substrates produced by high-temperature flash heating exploiting the spontaneous faceting of the Ge(001) surface close to the onset of surface melting. A very diverse growth mode is obtained depending on the specific atomic structure and step density of nearby surface domains with different vicinal crystallographic orientations. On highly-miscut areas of the Ge(001) substrate, the critical thickness for islanding is lowered to about 5 ML, in contrast to the 11 ML reported for the flat Ge(001) surface, while on unreconstructed (1x1) domains the growth is Volmer-Weber driven. An explanation is proposed considering the diverse relative contributions of step and surface energies on misoriented substrates. In addition, we show that the bottom-up pattern of the substrate naturally formed by thermal annealing determines a spatial correlation for the dot sites.
References in corpus (6)
- Melting and nonmelting of solid surfaces and nanosystems
- Measuring the surface stress polar dependence
- Evolution of coherent islands during strained-layer Volmer-Weber growth of Si on Ge(111)
- Ripple-to-dome transition: the growth evolution of Ge on vicinal Si(1 1 10) surface
- Si(111) strained layers on Ge(111): evidence for c(2x4) domains
- The stability of strained H:Si(105) and H:Ge(105) surfaces