SKM 2023 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 7: Poster I

HL 7.8: Poster

Montag, 27. März 2023, 13:00–15:00, P2/EG

Atomic structure of As-modified Si(100) surfaces prepared in CVD ambience — Manali Nandy¹, Agnieszka Paszuk¹, Oleksandr Romanyuk², •Chris Yannic Bohlemann¹, Aaron Flötotto³, Aaron Gieß¹, Peter Kleinschmidt¹, Ivan Gordeev², Jana Houdkova², Erich Runge³, and Thomas Hannappel¹ — ¹Fundamentals of Energy Materials, Institute of Physics, Ilmenau University of Technology, Ilmenau, Germany — ²Institute of Physics, Academy of Sciences of the Czech Republic, Prague, Czech Republic — ³Theoretical Physics 1, Institute of Physics, Ilmenau University of Technology, Ilmenau, Germany

For highly efficient III-V-on-Si devices, a low-defect III-V nucleation and a sharp interface are prerequisites. Stabilization of Si surfaces by arsenic is a promising technological step allowing to grow As-based III-V epitaxial layers in consecutive process steps. Here, we study the atomic structure of Si(100) surfaces prepared in As-rich ambiance utilizing MOCVD. Arsenic was supplied either directly via the precursor (TBAs) or indirectly as background As₄. The Si(100):As surfaces were analysed with a multitude of techniques such as STM, LEED, AR-XPS and FTIR after contamination-free transfer to ultra-high vacuum. The experimental results are supported by ab initio density functional theory (DFT) calculations. STM scans provide atomic-scale details of As-stabilized Si(100) surface structure consisting of rows of predominately asymmetric dimers. DFT simulations revealed a new stable structure with asymmetric As-Si-H dimers. The presence of hydrogen on the surface was confirmed by FTIR.