Reduced-Pressure Chemical Vapor Deposition Growth of Isolated Ge Crystals and Suspended Layers on Micrometric Si Pillars

Research output: Contribution to journalResearch articleContributedpeer-review


  • Oliver Skibitzki - , Innovations for High Performance Microelectronics (Author)
  • Giovanni Capellini - , Roma Tre University (Author)
  • Yuji Yamamoto - , Innovations for High Performance Microelectronics (Author)
  • Peter Zaumseil - , Innovations for High Performance Microelectronics (Author)
  • Markus Andreas Schubert - , Innovations for High Performance Microelectronics (Author)
  • Thomas Schroeder - , Brandenburg University of Technology (Author)
  • Andrea Ballabio - , Polytechnic University of Milan (Author)
  • Roberto Bergamaschini - , University of Milan - Bicocca (Author)
  • Marco Salvalaglio - , University of Milan - Bicocca, Technische Universität Dresden (Author)
  • Leo Miglio - , University of Milan - Bicocca (Author)
  • Francesco Montalenti - , University of Milan - Bicocca (Author)


In this work, we demonstrate the growth of Ge crystals and suspended continuous layers on Si(001) substrates deeply patterned in high aspect-ratio pillars. The material deposition was carried out in a commercial reduced-pressure chemical vapor deposition reactor, thus extending the "vertical-heteroepitaxy" technique developed by using the peculiar low energy plasma-enhanced chemical vapor deposition reactor, to widely available epitaxial tools. The growth process was thoroughly analyzed, from the formation of small initial seeds to the final coalescence into a continuous suspended layer, by means of scanning and transmission electron microscopy, X-ray diffraction, and mu-Raman spectroscopy. The preoxidation of the Si pillar sidewalls and the addition of hydrochloric gas in the reactants proved to be key to achieve highly selective Ge growth on the pillars top only, which, in turn, is needed to promote the formation of a continuous Ge layer. Thanks to continuum growth models, we were able to single out the different roles played by thermodynamics and kinetics in the deposition dynamics. We believe that our findings will open the way to the low-cost realization of tens of micrometers thick heteroepitaxial layer (e.g., Ge, SiC, and GaAs) on Si having high crystal quality.


Original languageEnglish
Pages (from-to)26374-26380
Number of pages7
JournalACS applied materials & interfaces
Issue number39
Publication statusPublished - 5 Oct 2016
Externally publishedYes

External IDs

Scopus 84990062961



  • virtual substrate, germanium, patterned Si, selective growth, vertical heteroepitaxy, growth dynamics simulation, dislocations, reduced pressure chemical vapor deosition, COALESCENCE, DIFFUSION, SURFACE