Controlled arrangement of self-organized Ge islands on patterned Si (001) substrates

Abstract

We report the ability to arrange self-organized Ge islands on patterned Si ͑001͒ substrates. Selective epitaxial growth of Si is carried out with gas-source molecular beam epitaxy to form Si mesas followed by subsequent Ge growth. Self-aligned and regularly spaced Ge islands are formed on the ͗110͘-oriented ridges of the Si stripe mesas. A mono-modal size distribution of the islands has been observed on the ridges. Using preferential nucleation sites allows us to place Ge islands at predetermined positions. The controlled arrangement of self-organized nanostructures offers the potential applications of island arrays for the implementation in nanoelectronics and quantum computation.

Si Based Nanostructure Growth Subsystem with Atomic Scale Control. Supersonic Molecular Beam Array Cell

“…Similar result was reported by other groups [25,26]. The perfect alignment of the dots along the Si stripe mesas is attributed to selfregulation mechanism driven by the minimization of the total energy, and also assisted by the formation of the ridges [27]. The tendency of Ge quantum dots to form on the ridge (or near the edge of a lattice step or the intersection of facet planes) is a result of stress-driven kinetics.…”

Advances in self‐assembled SiGe islands and nanostructures

“…This formed a template upon which Ge preferentially nucleated near the plateau edges forming a linear array of dots. Ge dot nucleation at the ridges of mesas have been obtained on Si patterned with stripes along the [110] direction due to anisotropy of the growth rate [27]. Si nanoimprinting at the 10-100 nm length scale has also been shown to be a good means to position Ge dots at a length scale difficult to attain by conventional lithography [28].…”

Lateral alignment of SiC dots on Si

“…Thus, the control of the nucleation sites of SiC is a precondition for a lateral alignment of the SiC nuclei. In the Ge cluster formation technology on Si several ways to localize the nucleation sites are known, e.g., ordering on lithographically pre-patterned substrates [9], on dislocation networks [10], and along step arrays on vicinal substrates [11]. The latter method of two-dimensional ordering has the advantage to not need additional processing steps.…”