Morphology of GaAs crystals heterogeneously integrated on nominal (001) Si by epitaxial lateral overgrowth on tunnel oxide via Ge nano-seeding

Marie Coste (1) , Timothée Molière (2) , Nikolay Cherkashin (3) , Géraldine Hallais (4) , Laetitia Vincent (5) , Daniel Bouchier (5) , Charles Renard (5, 2)

1 UGA UFRP - Université Grenoble Alpes - UFR Pharmacie
2 C2N (UMR_9001) - Centre de Nanosciences et Nanotechnologies
3 CEMES-MEM - Matériaux et dispositifs pour l'Electronique et le Magnétisme
4 Alchimer
5 IEF - Institut d'électronique fondamentale

In this study, GaAs crystals were grown by chemical beam epitaxy on nominal (001) Si substrate over Ge nano-seeds placed within nano-holes opened through a 0.6 nm silica layer. GaAs crystal morphology and atomic organization at the interface between Ge and GaAs were studied by using complementary Scanning Transmission Electron Microscopy, energy dispersive X-ray spectrometry and dark-field electron holography. Fourfold symmetry GaAs crystals were obtained and found to be completely relaxed and twin free. Thus, the use of Ge nano-seeds to initiate the growth of GaAs results in the suppression of twins previously observed for direct GaAs growth on nominal (001) Si. Nevertheless, anti-phase domains were detected. A simple atomistic model is proposed which explains how Anti-Phase Boundaries develop at the junctions between Ge {113} facets, and {113} and {111} facets for As-stabilized GaAs growth.

Domaines: Physique [physics]

Marie Coste, Timothée Molière, Nikolay Cherkashin, Géraldine Hallais, Laetitia Vincent, et al.. Morphology of GaAs crystals heterogeneously integrated on nominal (001) Si by epitaxial lateral overgrowth on tunnel oxide via Ge nano-seeding. Thin Solid Films, 2018, 647, pp.13-18. ⟨10.1016/j.tsf.2017.12.015⟩. ⟨hal-02322919⟩