Control of VW and SK growth modes in Ge quantum dot formation on Si(100) via carbon mediation

Control and mechanism analysis of Ge quantum dot (QD) formation on Si(100) by using two carbon (C) mediated methods, c(4×4) surface reconstruction (SR) and solid-phase epitaxy (SPE), was demonstrated for the first time. Si surface was reconstructed via the formation of C-Si bonds in advance of Ge deposition in SR method, QDs grew in Volmer-Wever mode due to the preferential nucleation on uncarbonized Si surface. Ge QDs were formed by annealing an amorphous Ge/C/Si heterostructure in SPE method, QDs grew in Stranski-Krastanov mode due to the incorporation of C-Ge bonds. Investigations, in this work, clarified that both c(4×4) surface reconstruction and strain relief played important roles through the analyses of surface morphology and C binding states.