| AVS 61st International Symposium & Exhibition | |
| Spectroscopic Ellipsometry Focus Topic | Thursday Sessions |
| Session EL+AS+EM+MC+SS-ThA |
| Session: | Optical Characterization of Nanostructures and Metamaterials |
| Presenter: | Greg Hearn, Accurion Inc. |
| Authors: | P.H. Thiesen, Accurion GmbH, Germany G. Hearn, Accurion Inc. B. Miller, Technische Universität München, Germany C. Röling, Accurion GmbH, Germany U. Wurstbauer, Columbia University E. Parzinger, Technische Universität München, Germany A.W. Holleitner, Technische Universität München, Germany U. Wurstbauer, Technische Universität München, Germany |
| Correspondent: | Click to Email |
In the initial period of graphene research, the issue was to identify and characterize crystallites of microscopic scale. Imaging ellipsometry is a nondestructive optical method in thin film metrology with a lateral resolution down to 1 µm. In a number of papers, Imaging ellipsometry has been applied to characterize graphene flakes of few micrometer size. Ellipsometric contrast micrographs, delta and Psi maps as well as wavelength spectra [1],[2] and single layer steps in multilayer graphene/graphite stacks [3] have been reported.
Molybdenum disulfide is a layered transition metal dichalcogenide. From the point of current research, 2D-nano materials based on MoS2 are very promising because of the special semiconducting properties. The bulk material has an indirect 1.2 eV electronic bandgap, but single layer MoS2 has a direct 1.8 eV bandgap. The monolayer can be used in prospective electronic devices like transistors (MOSFETs) or photo detectors. Delta and Psi Spectra of MoS2 monolayers as well as maps of the ellipsometric angles will be presented. The practical aspect of single layer identification will be addressed and the capability of ellipsometric contrast micrographs as a fast tool for single layer identification will be demonstrated.
An additional focus will be on the modelling of the optical properties of 2D nanomaterials.
[1] Wurstbauer et al., Appl. Phys. Lett. 97, 231901 (2010)
[2] Matkovic et al. J. Appl. Phys. 112, 123523 (2012)
[3] Albrektsen O. J. OF Appl. Phys. 111, 064305 (2012)