Berlin 2008 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 54: Si/Ge
HL 54.6: Vortrag
Freitag, 29. Februar 2008, 11:45–12:00, EW 202
Proton irradiation of germanium isotope multilayer structures — •Sebastian Schneider1, Hartmut Bracht1, Martin Petersen2, John Lundsgaard Hansen2, and Arne Nylandsted Larsen2 — 1Institute of Materials Physics, University of Münster, Germany — 2Department of Physics and Astronomy, University of Aarhus, Denmark
Irradiation of germanium (Ge) isotope heterostructures with 2.5 MeV protons have been performed at 550 deg C. The applied proton flux was varied between 1.0 and 1.5 microampere leading to various rates of Frenkel pair production. After rradiation, concentration profiles of the Ge-isotopes were recorded by means of secondary ion mass spectrometry. An inhomogeneous broadening of the isotope structure was observed that in addition to irradiation enhanced self-diffusion is affected by the formation of microscopic defects. Atomic force and scanning electron microscopy show that the microscopic defects are most probably resulting from an aggregation of vacancies formed during irradiation. Numerical analysis of Ge profiles not disturbed by microdefect formation indicates a significant contribution of self-interstitials to self-diffusion under irradiation.