Assembly of nanoelectronic device-structures on lithium niobate templates by means of Ferroelectric Lithography

• Applicant: Dr. Alexander Haußmann
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2014 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 235452448

A central challenge for contemporary nanotechnology is the production of functional nanodevices in a reproducible and parallel way by employing cost-efficient bottom-up methods. In order to accomplish this goal, ferroelectric templates are well suited, allowing for the controlled nanostructure self-assembly by the method known as "Ferroelectric Lithography" (FE-Litho).In FE-Litho, ferroelectric domain patterns direct the deposition of the nanostructures of your choice to the ferroelectric (FE) template. Since FE domains can be arbitrarily patterned with high accuracy over a broad size-range from nanometers to centimeters, FE-Litho not only is applicable for this bottom-up nano-engineering but, furthermore, excellently bridges the nano- to the macroscopic world with respect to integration and functionality.Lithium niobate (LiNbO3, LNO) is well suited as the FE template of our choice, since photochemical deposition of any species from the liquid phase is confined to adsorption to the ferroelectric domain wall (DW), only. Moreover, these 180° DWs in LNO measure less than 10 nm in width thus confining the deposition to a clearly defined nano-space.The first goal of this project hence is to make use of this challenging FE-Litho technique in order to build-up functional nanodevices, e.g. field effect transistors, bio assays, and coaxial nanocables, by employing carbon nanotubes (CNT), biological DNA molecules, and noble-metal nanowires as the building blocks, respectively. Our second goal is the thorough and fundamental investigation of the physical and chemical driving forces leading to this DW decoration process on LNO surfaces, which to date is still unclear.To achieve these aims, we plan to set up an in-situ and fully automated FE-Litho assembly platform based on a liquid-flow-cell including a scanning force microscope (AFM) mounted on top of an inverted UV-optical microscope. This setup then is used to accomplish all the preparation steps (e.g. UV-induced domain engineering, photochemical DW decoration, CNT sorting and deposition under laminar flow) as well as to perform the in-situ characterization using advanced AFM modes such as conductive AFM, piezo-response and Kelvin probe force microscopy.

• DFG Programme: Research Grants
• Major Instrumentation: Atomic Force Microscope and Microscope objective
• Instrumentation Group: 5091 Rasterkraft-Mikroskope