Regensburg 2010 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 36: Ge, GeSi, and Si

HL 36.3: Talk

Wednesday, March 24, 2010, 10:00–10:15, H14

The impact of interstitials on diffusion in germanium under proton irradiation — •Sebastian Schneider¹, Hartmut Bracht¹, Jan Klug², John Lundsgaard Hansen³, Arne Nylandsted Larsen³, Eugene Haller⁴, Dominique Bougeard⁵, Matthias Posselt⁶, and Clemens Wündisch⁶ — ¹Institut für Materialphysik, WWU Münster, Germany — ²Ruhr-Universiät, Bochum, Germany — ³Department of Physics and Astronomy, University of Aarhus, Denmark — ⁴MS and E Dept. University of California, Berkeley, U.S.A — ⁵Walter-Schottky-Institut, TU München, Germany — ⁶FZ Dresden-Rossendorf, Dresden, Germany

Experiments on the influence of 2.5 MeV proton irradiation on self- and dopant diffusion in germanium (Ge) were performed at 600 and 570^∘C, respectively. Ge isotope heterostructures consisting of 20 layers were used for the self-diffusion study. Ge with boron (B) doped multilayers and samples implanted with phosphorus (P) were utilized for the investigation of irradiation mediated dopant diffusion. Self-diffusion under irradiation reveals an unusual homogenous broadening of the isotope structure. This behaviour and the enhanced diffusion of B and retarded diffusion of P under irradiation demonstrates that an interstitial-mediated diffusion process dominates in Ge under irradiation. This discovery establishes new ways to suppress vacancy-mediated diffusion in Ge and to solve the donor deactivation problem that limits Ge-based nanoelectronics.