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arXiv · 1809.03404

Formation of extended thermal etch pits on annealed Ge wafers

L. Persichetti·M. Fanfoni·M. De Seta·L. Di Gaspare·L. Ottaviano·C. Goletti·A. Sgarlata
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Abstract

An extended formation of faceted pit-like defects on Ge(001) and Ge(111) wafers was obtained by thermal cycles to T> 750 °C. This temperature range is relevant in many surface-preparation recipes of the Ge surface. The density of the defects depends on the temperature reached, the number of annealing cycles performed and correlates to the surface-energy stability of the specific crystal orientation. We propose that the pits were formed by preferential desorption from the strained regions around dislocation pile-ups. Indeed, the morphology of the pits was the same as that observed for preferential chemical etching of dislocations while the spatial distribution of the pits was clearly non-Poissonian in line with mutual interactions between the core dislocations.

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L. Persichetti, M. Fanfoni, M. De Seta, L. Di Gaspare, L. Ottaviano, C. Goletti, A. Sgarlata. 2018-09-10. Formation of extended thermal etch pits on annealed Ge wafers. https://doi.org/10.1016/j.apsusc.2018.08.075

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