Growth kinetics of Ge crystals on silicon oxide by nanoscale silicon seed induced lateral epitaxy

• Published in: Journal of applied physics 2009-11, Vol.106 (9)
• Main Authors: Cammilleri, V. D., Yam, V., Fossard, F., Renard, C., Bouchier, D., Fazzini, P. F., Hÿtch, M.
• Format: Article
• Language: English
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.3245329

In this paper, we present our studies on the growth kinetics of Ge crystals on silicon oxide by nanoscale seed induced lateral epitaxy. We propose a simple and reliable method based on standard local oxidation of silicon technique for creating nanoscale silicon seeds at the edge of thermally grown silicon oxide stripes of desired thickness. The growth of Ge from germane is initiated in the two silicon seed lines and evolves toward a complete wetting of the SiO2 stripe after coalescence. The wetting mechanism of SiO2 by Ge is strongly dependent on the seed orientation and closely related to the development of {111} facets. The coalescence of adjacent Ge crystals results in an improvement in the organization of the initial material. As a result, no defect is visible in the inner part of the structure. The observed defects are arrays of misfit dislocations standing along the seed lines, while only few dislocations are visible through the Ge crystal. Geometric phase analysis of high resolution transmission electron microscopy images and x-ray diffraction reciprocal space maps show that the so-grown Ge crystal stripes on SiO2 layer are fully relaxed, homogeneous, and fully coherent along their length. The main deviation regarding a perfect epitaxial relation with the silicon substrate is a tilt of ±0.6° around the longitudinal axis of stripe crystals.