Dresden 2017 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 50: Semiconductor Substrates: Structure, Epitaxy, Growth and Adsorption

O 50.6: Poster

Dienstag, 21. März 2017, 18:30–20:30, P1A

As-modification of vicinal Si(100) surfaces for III-V-on-Si heteroepitaxy in CVD ambient — •Agnieszka Paszuk¹, Oliver Supplie¹, Sebastian Brückner¹, Peter Kleinschmidt¹, Anja Dobrich¹, Andreas Nägelein¹, Matthias M. May², and Thomas Hannappel¹ — ¹Institute of Physics, Technische Universität Ilmenau, Germany — ²Department of Chemistry, Cambridge University, UK

Compound semiconductors grown on Si substrates are attractive for high efficiency solar cells, optoelectronic and microelectronic devices. Growth of III-V materials with low defect densities on Si is challenging due to lattice mismatch and different thermal expansion coefficients, as well as polar-on-nonpolar epitaxy. Arsenic (As) enables growth of ternary compounds, such as GaAsP, and As is mostly present in application-relevant III-V MOCVD reactors. We previously showed that dedicated As-modification of the heterointerface is suitable to control the III-V sublattice orientation [1]. Here, we will study the dimer orientation on vicinal Si(100) surface prepared in As-rich MOCVD ambient. The entire process is controlled by in situ reflection anisotropy spectroscopy (RAS) and the obtained RA spectra are benchmarked by LEED and XPS. We show that the RAS signal is not only terrace-related (As-coverage, type and orientation of the dimers) but it also can contain contributions from the step structure. We achieve in situ control of the majority dimer orientation on As-modified Si(100) surfaces and can thereby choose the sublattice orientation of the subsequently grown, single-domain III-V epilayer. [1] A.Paszuk et al., APL 106, 231601 (2015); O. Supplie et al., APL Mater.3,126110 (2015).