Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf
Quantitative Kelvin probe force microscopy on semiconductors under ambient conditions
Baumgart, C.; Müller, A.-D.; Müller, F.; Helm, M.; Schmidt, H.
Failure analysis and optimization of nanoelectronic devices require knowledge of their electrical properties. Kelvin probe force microscopy (KPFM) is a standard technique for the investigation of the surface potential. We present its applicability to locally doped semiconductors. Quantitative dopant profiling by means of KPFM is successfully shown on a conventional static random access memory (SRAM) cell and on cross-sectionally prepared Si epilayer structures by applying a recently introduced new explanation of the measured KPFM signal . The presented KPFM model is also used to explain observed large conductivity differences in different Mn implanted and pulsed laser annealed Ge samples by revealing a strong variation of the Fermi level position on the µm scale in dependence on the annealing conditions .
In addition, the frequency dependence of the Kelvin bias above differently doped regions is discussed with respect to surface states and trapped charges in the thin oxide layer on top . Using an active mixer, the excitation amplitude of the cantilever is almost independent of the operation frequency. As a result, KPFM measurements have to be performed at frequencies high enough so that the electrical properties of the locally doped semiconductor and not of the oxide layer are probed.
 C. Baumgart, M. Helm, H. Schmidt, Phys. Rev. B 80, 085305 (2009).
 S. Zhou, D. Bürger, A. Mücklich, C. Baumgart, W. Skorupa, C. Timm, P. Oesterlin, M. Helm, and H. Schmidt, Phys. Rev. B 81 (2010), 165204.
 F. Müller and A.-D. Müller, J. Vac. Sci. Techn. B 27, 969 (2009).
- DOI: 10.17815/jlsrf-3-159 is cited by this (Id 14373) publication
Nanofair 2010, 06.-07.07.2010, Dresden, Germany