Oxide thickness mapping of ultrathin Al2O3 at nanometer scale with conducting at

2019-11-20 08:42:04

thickness Local atomic oxide microscopy

责任者: Olbrich, A.;Ebersberger, B.;Boit, C.;Vancea, J.;Hoffmann, H.;Altmann, H.;Gieres, G.;Wecker, J. 单位: Failure Anal., Munich, Germany 来源出处: Applied Physics Letters(Appl. Phys. Lett. (USA)),2001/05/07,78(19):2934-6 摘要: In this work, we introduce conducting atomic force microscopy (C-AFM) for the quantitative electrical characterization of ultrathin Al2O3 films on a nanometer scale length. By applying a voltage between the AFM tip and the conductive Co substrate direct tunneling currents in the sub pA range are measured simultaneously to the oxide surface topography. From the microscopic I-V characteristics the local oxide thickness can be obtained with an accuracy of 0.03 nm. A conversion scheme was developed, which allows the calculation of three-dimensional maps of the local electrical oxide thickness with sub-angstrom thickness resolution and nanometer lateral resolution from the tunneling current images. Local tunneling current variations of up to three decades are correlated with the topography and local variations of the electrical oxide thickness of only a few angstroms 关键词: alumina;atomic force microscopy;insulating thin films;surface topography;thickness measurement;tunnelling;ultrathin films;thickness mapping;conducting atomic force microscopy;AFM;conductive Co substrate;direct tunneling currents;I-V characteristics;local oxide thickness;surface topography;Al2O3;Co