|Project No.||Project Name||Responsible|
Structural and morphological characterization of nanoscaled interconnect systems
|Prof. Dr. Michael HIETSCHOLD|
Microelectronic structures are mainly governed by their structural and electronic properties at the relevant interfaces. The analysis of these surfaces and interfaces with high spatial resolution is mandatory for the development of reliable technologies.
Scanning probe microscopic methods and electron microscopy are established techniques for such type of investigations. The applicant with his group has long-term experience in these fields.
In the present subproject, atomic force microscopy (AFM) and scanning electron microscopy (SEM) will be applied as standard imaging techniques. The interfaces of interest have to be prepared mainly as cross-sections. The most innovative aspects are connected with the application of scanning electrical force microscopy (SEFM) and high-resolution transmission electron (HRTEM) microscopy as well as with the usage of a novel argon ion-milling technique for cross-sectional sample preparation.
SEFM enables simultaneous mapping of surface topography, local surface potential distribution and mapping of the local tip-sample capacitance (which visualizes the local electronic surface properties). HRTEM of interfaces gives direct information about the atomic interface structure including local defects down to the atomic scale. Complementary electron diffraction (especially selected area diffraction) allows determination of the real crystallographic interface situation. Electron energy-loss spectroscopy (EELS) in connection with an energy filter makes elemental mapping possible. These methods are especially valuable for the detailed investigation of diffusion barriers.
Advanced analytical SEM recently available in our research group after a successful HBFG application allows low-voltage imaging which is especially suitable for non-conducting materials such as low-k dielectrics and electron backscatter diffraction (EBSD) which is a complementary tool for texture analysis to X-ray based methods.
The preparation method to be used is very special: It has been developed recently in the group of the applicant together with the company BALTEC AG, and uses the combination of a classical argon ion milling with in-situ electron-microscopic visualization (both SE as well as TE observation modus). This novel method avoids sample contamination, which may occur during similar preparation with focused ion beam (FIB) methods. The sub-project will give a great opportunity for an optimization of the method and for detailed comparison with FIB preparation.
The group is also well prepared to participate in the long-term challenges of the IRTG research program: Self-assembly of ultrathin organic molecular films [G8-1, G8-2] as well as first steps towards the implementation of molecular devices on 2d patterned surfaces [G8-3, G8-4] have been attempted recently.
Cooperation with the German subprojects G1 (Gessner), G4 (Reichl), G5 (Lang) regarding sample characterization is planned, while interaction with G6 (Richter) and G7 (Zahn) will help correlate the findings with other materials characterization methods. In the same manner, cooperation is envisaged with the Chinese subprojects F1 (Xuejian Yan), F2 (Wei Zhang), F3 (Xinping Qu), F6 (Wenbin Cai), and F7 (Ran Liu).
|[G8-1]||M. Lackinger, S. Griessl, W.M. Heckl, M. Hietschold: "STM and STS of coronene on HOPG (0001) in UHV - adsorption of the smallest possible graphite flakes on graphite", Anal. & Bioanal. Chem. 374 (2002), 685|
|[G8-2]||S. Griessl, M. Lackinger, M. Edelwirth, M. Hietschold, W.M. Heckl: "Self-assembled two-dimensional molecular host-guest architectures from trimesic acid", Single Mol. 3 (2002), 25|
|[G8-3]||S.J.H. Griessl, M. Lackinger, F. Jamitzky, T. Markert, M. Hietschold, W.M. Heckl: "Room temperature STM manipulation of single C60 molecules at the liquid solid interface - playing nano-soccer", J. Phys. Chem. B 108 (2004), 11556|
|[G8-4]||S.J.H. Griessl, M. Lackinger, F. Jamitzky, Th. Markert, M. Hietschold, W.M. Heckl: "Incorporation and manipulation of coronene in an organic template structure", Langmuir 20 (2004), 9403|