Dresden 2006 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

HL: Halbleiterphysik

HL 9: Poster I

HL 9.20: Poster

Montag, 27. März 2006, 15:15–17:45, P3

Slow, focused ion beam (FIB) meet high-purity layers: combined MBE-low-energy-FIB facility to creat shallow, overgrown doped layers — •Sinan Ünlübayir, Dirk Reuter, Alexander Melnikov, and Andreas D. Wieck — Ruhr-Universität Bochum, Universitätsstraße 150, 44801 Bochum

We have modified a commercial focused ion beam (FIB) to allow usage in a variable energy range between only 10 eV to 30 keV. To slow down the ions, a retarding field between the sample stage and a FIB column is applied. In case of slow ion implantation it is common to speak about deposition, because the depth of penetration is few nanometer, or around one monolayer. The FIB is connected with a ultra high vacuum lock to a III/V molecular beam epitaxy system. This enable us to overgrow the implanted regions after transferring into the MBE chamber. With this technique we have embeded lateral, shallow doped regions into GaAs or AlGaAs. The present work discussed about Si- and Be-doped layers in GaAs, which are produced by ion energy between 10 eV to 1000 eV. Furthermore we doped GaAs/Al_xGa_1−xAs-Heterostructures ( so-called HEMTs) with this Si deposition technique. It will be showed that, production of two dimensional electron gases (2DEG) is achieved. The samples have been examined by means of Hall and magneto transport measurements at low temperatures. The smallest lateral size of the doped layer obtained by us was 5 µm. To the best of the authors knowledge, this is the smallest size reported elsewhere.