An extended formation of faceted pit-like defects on Ge(0 0 1) and Ge(1 1 1) 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.
Persichetti, L., Fanfoni, M., De Seta, M., Di Gaspare, L., Ottaviano, L., Goletti, C., et al. (2018). Formation of extended thermal etch pits on annealed Ge wafers. APPLIED SURFACE SCIENCE, 462, 86-94 [10.1016/j.apsusc.2018.08.075].
Formation of extended thermal etch pits on annealed Ge wafers
Persichetti, L.;Fanfoni, M.;Goletti, C.;Sgarlata, A.
2018-01-01
Abstract
An extended formation of faceted pit-like defects on Ge(0 0 1) and Ge(1 1 1) 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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
