Berlin 2012 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 63: Devices I
HL 63.1: Vortrag
Mittwoch, 28. März 2012, 15:00–15:15, EW 015
Mapping of reflectivity and excited carriers’ transport in metal–insulator–metal heterosystems — Dominik Differt1, Walter Pfeiffer1, and •Detlef Diesing2 — 1Universität Bielefeld, Universitätsstr. 25, 33615 Bielefeld, Germany — 2Fakultät für Chemie, Universität Duisburg-Essen, D-45117 Essen, Germany
The quality of large area thin film metal heterojunctions with interstitial oxide layers depends on the lateral homogeneity of the metal thicknesses and the interstitial oxide’s barrier height. Lateral inhomogeneities on the microscopic scale may lead to changed properties of the macroscopic device. We present a new setup which enables the mapping of surface reflectivity and of photo excited carriers transport as well. For the lateral mapping of the internal photo emission (IPE) in a Ag-TaO-Ta heterosystem the sample is raster scanned across the focus of a Schwarzschild objective (NA=0.4). The illumination with 400 nm laser radiation results in a focus diameter of 5 µ m limiting the spatial resolution of the IPE microscope. Mapping across the 40 µ m wide edge of the top metal film shows transport effects in the top silver electrode as well as the increasing excitation of carriers in the tantalum backelectrode with decrasing top electrode thickness. The spatial variation of the top electrode thickness at the edge of the electrode gives information about the relaxation dynamics of the photo excited carriers.