Formation of Self-Connected Si0.8Ge0.2 Lateral Nanowires and Pyramids on Rib-Patterned Si(1 1 10) Substrate

Nanoscale Res Lett. 2017 Dec;12(1):70. doi: 10.1186/s11671-016-1820-z. Epub 2017 Jan 24.

Abstract

In this work, Si0.8Ge0.2 is deposited onto the rib-patterned Si (1 1 10) template oriented in the [1 -1 0] direction. Atomic force microscopy (AFM) reveals that the rib sidewalls reshape into pyramid-covered (0 0 1) and smooth {1 1 3} facets, respectively, while the {1 0 5} facets-bounded lateral SiGe nanowires dominate the rib top along the [5 5 -1] direction. At both the rib shoulder sites and the pyramid vacancy sites, self-connecting occurs between the meeting nanowire and pyramids to form elongated huts, which are driven by the minimization of the total energy density according to the finite-element simulations results. These results suggest a convenient solution to form lateral SiGe nanowires covering multi-faceted surfaces on the patterned template.

Keywords: Finite-element simulation; Germanium; Lateral nanowires; Molecular beam epitaxy; Patterned template.