Sub - 10 nm nanotransfer printing using MBE stamps for novel applications in organic and molecular electronics
Experimental Condensed Matter Physics
Final Report Abstract
Within this project, important fundamental knowledge could be gained about use of nanoimprint and nanotransfer techniques for the realization of electronic devices. We have demonstrated that nanostructures of sizes down to few tens of nanometers can be successfully transferred on silicon substrates and can be the basis for a variety of novel devices. Metal electrodes can also be fabricated which extend the tools available in the field of organic and printed electronics. Thanks to the methodology developed in the project, electronic properties of certain organophosphonate monolayer systems on aluminum oxide surfaces could be studied extensively. These monolayers have proven to be versatile interface systems that shall be further exploited for nanoelectronic applications in future research. In particular, alkyl mono- and bisphosphonates (monoPAs and bisPAs, respectively) of different carbon chain length were deposited on aluminum oxide surfaces and their electronic characteristics were investigated. Bis-phosphonate monolayers showed an intriguing, non-trivial dependence of the film resistance as function of film thickness which may well become important for applications as gate dielectric or insulation layer. Bis-phosphonate monolayers were also found to be highly effective as functional adhesive interface for the direct printing of metal contacts onto solid surfaces. This is a major step towards further developing transistor structures based on such printed-electrode schemes. For any related monolayer fieldeffect transistor structure in addition, proper electronic function of the organic conductive thin film has to be demonstrated. Using a silicon-only nanogap device structure, functionalized with a monolayer of an anthracene-based organophosphonate, such first demonstration was successfully achieved. Using MBE-grown AlGaAs/GaAs heterostructures a completely new manufacturing process, involving new geometries and a dedicated printing setup was successfully developed. Large transferred thin-film metal areas in particular comprising long linear gaps with widths down to about 10 nm could be demonstrated. Here, a particular focus was understanding the intriguing influence of the various process parameters (metal material, gap etching chemistry, surface pre-treatment, atmosphere, pressure, time, temperature etc.) on the printing result. By carefully investigating the (partially) interdependent parameters optimal settings for best transfer yields could be obtained. Complex stamps, which comprised patterned gap regions by on-face lithography, were demonstrated, and CEO stamps for printing T-shaped patterns were successfully grown and characterized. Systematic transfer studies using these novel CEO structures will be carried out in future studies.
Publications
- (2016) Disorder-derived, strong tunneling attenuation in bis-phosphonate monolayers. Journal of physics. Condensed matter : an Institute of Physics journal 28 (9) 094008
Pathak, Anshuma; Bora, Achyut; Liao, Kung-Ching; Schmolke, Hannah; Jung, Antje; Klages, Claus-Peter; Schwartz, Jeffrey; Tornow, Marc
(See online at https://doi.org/10.1088/0953-8984/28/9/094008) - (2017) Nanocylindrical confinement imparts highest structural order in molecular self-assembly of organophosphonates on aluminum oxide. Nanoscale 9 (19) 6291–6295
Pathak, Anshuma; Bora, Achyut; Braunschweig, Björn; Meltzer, Christian; Yan, Hongdan; Lemmens, Peter; Daum, Winfried; Schwartz, Jeffrey; Tornow, Marc
(See online at https://doi.org/10.1039/c7nr02420g) - Carbon nanotube thin-film transistors featuring transfer-printed metal electrodes and a thin, self-grown aluminum oxide gate dielectric, 2015 IEEE 15th International Conference on Nanotechnology (IEEE-NANO), 160 (2015)
T. Haeberle, F. Loghin, U. Zschieschang, H. Klauk and P. Lugli
(See online at https://dx.doi.org/10.1109/NANO.2015.7388946) - High-yield metal transfer printing on alkyl bis-phosphonate monolayers. Proceedings of the 15th IEEE International Conference on Nanotechnology July 27-30, 2015, Rome, Italy, p. 1559
Anshuma Pathak, Tobias Haeberle, Achyut Bora, Jeffrey Schwartz, Paolo Lugli, Marc Tornow
(See online at https://dx.doi.org/10.1109/NANO.2015.7485973) - A Nanogap Electrode Platform for Organic Monolayer-Film Devices. Proceedings of the 16th IEEE International Conference on Nanotechnology August 22-25, 2016, Sendai, Japan, p. 842
Simon Pfaehler, Kevin Keim, Réka Csiki, Quoc Hung Nguyen, Kung-Ching Liao, Martin Stutzmann, Jeffrey Schwartz, Anna Cattani-Scholz, Marc Tornow
(See online at https://dx.doi.org/10.1109/NANO.2016.7751507) - Large Area Nanotransfer Printing of Sub-50-nm Metal Nanostructures Using Low-cost Semi-flexible Hybrid Templates, Nanoscale Research Letters 11, 562 (2016)
R. D. Nagel, T. Haeberle, M. Schmidt, P. Lugli and G. Scarpa
(See online at https://doi.org/10.1186/s11671-016-1346-4)
