AVS 52nd International Symposium
    Applied Surface Science Monday Sessions
       Session AS-MoA

Paper AS-MoA6
Workfunction Differences between Cu Grains: Laterally Resolved UPS with the NanoESCA

Monday, October 31, 2005, 3:40 pm, Room 206

Session: Electron Spectroscopies
Presenter: J. Westermann, Omicron NanoTechnology GmbH, Germany
Authors: J. Westermann, Omicron NanoTechnology GmbH, Germany
D. Funnemann, Omicron NanoTechnology GmbH, Germany
B. Kroemker, Omicron NanoTechnology GmbH, Germany
Correspondent: Click to Email
Recently, we have developed an Imaging XPS spectrometer with lateral resolution in the range of 200nm and below.@footnote 1,2@ This instrument has recently been used for the study of work function differences on a variety of samples. Main focus of this application was the work function variation between different copper grains. As copper is currently of great interest as a material for interconnects in semiconductor devices, the understanding of grain properties is a key for the improvement of the interconnect properties. Samples were provided by the Laboratoire d'Electronique de Technologie de l'Information (LETI, Grenoble). Using the NanoESCA, we can show for the first time the relation between secondary electron intensity and work function with a high spatial resolution. Surprisingly, this does not follow the Fowler plot as was expected previously.@footnote 3@ In addition, we show measurements on a heterogenous material combination with microstructured Gold patterns on a Silicon Oxide sample. These data demonstrate the powerful combination of imaging with spectroscopy: We identify regions of band-bending, charging and different work-functions. @FootnoteText@ @footnote 1@ Escher et al., J.Phys.:Condens. Matt 17 (2005) 1329-1338@footnote 2@ Escher et al., J. Electron Spectrosc. Relat. Phenom., 144-147 (2005) 1179-1182@footnote 3@ Przychowski et al., Surf. Sci. 549 (2004) 37-51.