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Special scanning tunneling microscope (STM) holders have been developed in order to simultaneously record electronic conductance, mechanical properties [2], and structural change of nanostructures and films in EMs, especially in TEMs or STEMs. Spence et al. developed a STM setup that was applied in a reflection electron microscope (REM) [3, 4]. Later, more STM-TEM holders have been proposed. The STM tip can move in three-dimensions (x, y, and z). For instance, in electrical measurements, the electronic conductance can be obtained at intervals of 20 ms, and high-resolution TEM images can be recorded on videotape at 30 fps. In these measurements, the vacuum in the specimen region must be very high in order to avoid contamination as the current–voltage (I–V) characteristics are very sensitive to interfacial contamination [5]. An example of STM-TEM holders is shown in Figure 2573. [1] The STM-TEM holder has both specimen and tip stages. The holder allows coarse as well as fine movements. Coarse movement is induced by an inchworm (made by Burleigh Co.), allowing 5 mm translation, while fine movement is generated by a tube piezo scanner, providing 1 µm scanning in three-dimensions. The STM holder was made of copper beryllium alloy. However, an objective pole piece (OPP) has been specially designed for this application.
Figure 2573. (a) Photograph of a STM-TEM holder, and (b) Schematic illustration of the STM-TEM holder head. Adapted from [1]
[1] Y. Oshima, K. Mouri, H. Hirayama, K. Takayanagi, Development of a miniature STM holder for study of electronic conductance of metal nanowires in UHV–TEM, Surface Science 531 (2003) 209–216.
[2] Y. Naitoh,K. Takayanagi, H. Hirayama, Y. Oshima, Surf.
Sci. 433–435 (1999) 627.
[3] M. Kuwabara,W. Lo, J.H.C. Spence,J. Vac. Sci. Technol.
A 7 (1989) 2745.
[4] M. Iwatsuki,K. Murooka, S. Kitamura,K. Takayanagi,
Y. Harada,J. Electron. Microsc. 40 (1991) 48.
[5] K. Hansen,S.K. Nielsen,M. Brandbyge,E. Lægsgaard,I.
Stensgaard,F. Besenbacher, Appl. Phys. Lett. 77 (2000)
708.
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