A self-ordered, body-centered tetragonal superlattice of SiGe nanodot growth by reduced pressure CVD. (9th November 2017)

• Record Type: Journal Article
• Authors: Yamamoto, Yuji; Zaumseil, Peter; Capellini, Giovanni; Andreas Schubert, Markus; Hesse, Anne; Albani, Marco; Bergamaschini, Roberto; Montalenti, Francesco; Schroeder, Thomas; Tillack, Bernd
• Is Part Of: Nanotechnology. Volume 28:Number 48(2017)
• Publication Date: 2017-11-09
• Subjects: chemical vapor deposition -- epitaxy -- SiGe -- nanodot -- self-ordering; 81.15.Gh -- 62.23.Eg; Nanotechnology -- Periodicals; Nanotechnology -- Periodicals; Nanotechnology; Publications périodiques; Nanotechnologies; Periodicals; 620.5
• DOI: 10.1088/1361-6528/aa91c1
• Languages: English
• ISSNs: 0957-4484

Abstract

Abstract: Self-ordered three-dimensional body-centered tetragonal (BCT) SiGe nanodot structures are fabricated by depositing SiGe/Si superlattice layer stacks using reduced pressure chemical vapor deposition. For high enough Ge content in the island (>30%) and deposition temperature of the Si spacer layers ( T > 700 °C), we observe the formation of an ordered array with islands arranged in staggered position in adjacent layers. The in plane periodicity of the islands can be selected by a suitable choice of the annealing temperature before the Si spacer layer growth and of the SiGe dot volume, while only a weak influence of the Ge concentration is observed. Phase-field simulations are used to clarify the driving force determining the observed BCT ordering, shedding light on the competition between heteroepitaxial strain and surface-energy minimization in the presence of a non-negligible surface roughness.