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DS: Fachverband Dünne Schichten

DS 17: Ion and Electron Beam Induced Processes

DS 17.1: Vortrag

Dienstag, 1. April 2014, 14:00–14:15, CHE 91

Reverse Epitaxy — •Xin Ou, Adrian Keller, Manfred Helm, Jürgen Fassbender, and Stefan Facsko — Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR) e.V., P.O. Box 510119, 01314 Dresden, Germany.

Based on a self-organized ion beam erosion process, periodic ripple, hole, or dot arrays can be produced on various semiconductor surfaces. However, the main drawback of this method is that the irradiated semiconductor surfaces are amorphized. For device fabrication, a crystalline surface of high quality is indispensable. In this work we report the recent discovery of single crystal Ge nanopattern surface formation based on a *reverse epitaxy* process at elevated temperature.[1] The vacancies created during ion beam irradiation distribute according to the crystallographic anisotropy, which results in an orientation-dependent pattern formation on single crystal Ge surface. This process shows nicely the equivalence of epitaxy with deposited adatoms and *reverse epitaxy* with ion induced surface vacancies on semiconductors, and the formation of these patterns is interpreted as the result of a surface instability due to an Ehrlich-Schwoebel barrier for ion induced surface vacancies. The simulation of the pattern formation is performed by a continuum equation accounting for the effective surface currents. [1] Xin Ou et al., Phys. Rev. Lett. 111, 016101 (2013).