Structure and morphology of Ge nanowires on Si(001): Importance of the Ge islands on the growth direction and twin formation

Frédéric Boudaa (1) , Nicholas Blanchard (2) , A. Descamps-Mandine (3) , Aziz Benamrouche (3) , Michel Gendry (1) , Jose Penuelas (1)

1 INL - H&N - INL - Hétéroepitaxie et Nanostructures
2 ILM - Institut Lumière Matière [Villeurbanne]
3 INL - Nanolyon - INL - Plateforme Technologique Nanolyon

Understanding and controlling the structural properties of Ge nanowires are important for their current and future use in technological applications. In this study, the initial stages of the heteroepitaxial growth of Ge nanowires on Si(001) via the Au catalyzed vapor-liquid-solid (VLS) method are investigated. We observe a Ge island located at the base of each nanowire. We propose that these islands are formed by the VLS mechanism and initiate the nanowire growth. Analysis of the islands morphology helps to explain the 〈011〉 growth direction commonly observed for Ge nanowires. Moreover, our observations provide an insight into the formation of twins that propagate along the growth direction.

Domaines: Sciences de l'ingénieur [physics]; Optique / photonique; Matériaux; Micro et nanotechnologies/Microélectronique

Frédéric Boudaa, Nicholas Blanchard, A. Descamps-Mandine, Aziz Benamrouche, Michel Gendry, et al.. Structure and morphology of Ge nanowires on Si(001): Importance of the Ge islands on the growth direction and twin formation. Journal of Applied Physics, 2015, 117, pp.055302. ⟨10.1063/1.4907684⟩. ⟨hal-01489327⟩