SKM 2023 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 7: Poster I
HL 7.8: Poster
Monday, March 27, 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.