2009.12.07

Audiotorium, Eigineering 9th Bld, Hongo Campus

Prof. Klaus van Benthem
   University of California Davis Department of Chemical Engineering and Materials Science

Title: New Prospects of Aberration corrected Scanning Transmission　Electron Microscopy

Abstract:

Aberration-corrected scanning transmission electron microscopy (STEM) enables the structural and chemical characterization of defect structures with sub-Ångström spatial resolution and single atom sensitivity. The reduced depth of field after aberration correction further provides depth sensitivity to obtain three-dimensional information of the sample [1].
Two prominent examples about the application of such techniques will be reported: the localization of single Hf atoms within a multilayered semiconductor device structure[2-4]; and the identification of interstitial point defect configurations in silicon [5]. For both applications, defect structures will be discussed in the framework of their influence on macroscopic properties.
During the final part of the presentation, in situ STEM techniques will be discussed that offer novel capabilities to characterize the evolution of atomic-scale defect structures under applied stress, such as heat, electrical fields and currents. First preliminary results will be reported, ranging from the dewetting of ultra-thin films on crystalline substrates, dielectric breakdown of CMOS devices, and pressure-less consolidation of ceramic powders.

1. van Benthem K, Lupini AR, Kim M, Baik HS, Doh S, Lee JH, et al. Three-dimensional imaging of individual hafnium atoms inside a semiconductor device. Appl Phys Lett 87 (2005) 3
2. Bersuker G, Park CS, Barnett J, Lysaght PS, Kirsch PD, Young CD, et al. The effect of interfacial layer properties on the performance of Hf-based gate stack devices. Journal of Applied Physics 100 (2006) 6
3. Marinopoulos AG, van Benthem K, Rashkeev SN, Pennycook SJ, Pantelides ST. Impurity segregation and ordering in Si/SiO2/HfO2 structures. Physical Review B 77 (2008) 6
4. van Benthem K, Pennycook SJ. Imaging and spectroscopy of defects in semiconductors using aberration-corrected STEM. Appl Phys A-Mater Sci Process 96 (2009) 161-9
5. Oh SH, van Benthem K, Molina SI, Borisevich AY, Luo WD, Werner P, et al. Point defect configurations of supersaturated Au atoms inside Si nanowires. Nano Lett 8 (2008) 1016-9

Schedule: 16:00  ~ 17:30  Monday 7th December, 2009

Place: Audiotorium, Eigineering 9th Bld, Asano Campus

Attached file:  37th open seminar.pdf