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HL: Fachverband Halbleiterphysik

HL 93: III-V semiconductors (other than nitrides)

HL 93.4: Vortrag

Donnerstag, 19. März 2015, 16:30–16:45, EW 203

HR-XRD analysis on GaP rotational twin domains on Si(111) substrates — •Christian Koppka, Agnieszka Paszuk, Matthias Steidl, Katja Tonisch, and Thomas Hannappel — Technische Universität Ilmenau, FG Photovoltaik, 98693 Ilmenau, Deutschland

The combination of todays silicon technology with tunable III-V semiconductors is of great interest for future high-efficiency optoelectronic devices. Due to the small lattice mismatch GaP/Si is a suitable quasi-substrate to link non-polar silicon substrates and polar III/V layers. For the growth of nanowire-based semiconductor structures {111} oriented substrates are commonly used. Here, rotational twin domains are a major defect, which cannot easily be suppressed by the substrate surface structure. Low defect densities, however, are required for further III/V integration. A reliable quantification of the rotational domain ratio is essential in order to adjust the MOCVD process for growth of single crystal GaP epilayers on Si(111). Here, we use high-resolution x-ray diffraction analysis for quantification and investigate the influence of various parameters, such as growth temperature, III:V ratio and surface terminations, on the twin domain ratio. We find that growth temperature and Si surface termination prior nucleation highly impact the GaP(111) epilayer growth.