Berlin 2008 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
HL: Fachverband Halbleiterphysik
HL 10: Preparation and characterization
HL 10.3: Vortrag
Montag, 25. Februar 2008, 10:00–10:15, EW 202
Probing the free charge carrier distribution with non-contact and contact AFM — •A.-D. Müller1, F. Müller1, S. Jänsch2, C. Henkel2, P. Pelzing3, A. Möller3, and H. Schmidt4 — 1Anfatec Instruments AG, Melanchthonstrasse 28, D-08606 Oelsnitz — 2Universität Leipzig, Institut für Experimentelle Physik II, D-04103 Leipzig — 3SGS Institut Fresenius GmbH, D-01109 Dresden — 4Forschungszentrum Dresden-Rossendorf e.V., D-01314 Dresden
We address the issue of extracting the dopant profile information on the nanoscale by electrostatic force microscopy (EFM) in non-contact and Scanning Capacitance Microscopy (SCM) in contact mode. Cross sections prepared of Si epilayers on Si substrates were investigated with highly-doped conductive tips in complementary SPM techniques with a lateral resolution limited by the Debye length. Frequency and tip-sample distance dependent surface work functions were obtained by Kelvin Probe Force Microscopy (KPFM) with a voltage resolution better than 10 meV. Surface band structures in the frequency range between 10 kHz and 300 kHz are acquired by non-contact capacitance detection in dynamic EFM, while high-frequency tip-sample capacitance-voltage characteristics have been detected by a SCM sensor and enable the determination of dopant concentration. The comparison between these techniques is completed by numerical simulations of voltage dependent tip-sample capacitances to improve the understanding of the contrast. The recorded KPFM and SCM data are complementary with respect to surface and depth resolution, respectively, and together they give a more complete impression of the sample's electronic structure.