Tip-based nanomanufacturing and metrology of heterogeneous nanostructures

This dissertation presents controlled fabrication and chemical identification of heterogeneous nanostructures using atomic force microscope (AFM) cantilevers. Fabrication and integration of different chemical structures at the nanometer scale is essential for constructing the next generation of electrical, optical, and biological devices. The polymer nanostructures are fabricated using thermal dip pen nanolithography (tDPN), and are characterized using atomic force microscope infrared spectroscopy (AFM-IR). In tDPN, the heated tip of an atomic force microscope cantilever deposits polymer nanostructures onto a surface, where the cantilever heating controls the deposition rate. The nanometer-scale polymer transport between the tip and surface is investigated by controlling tip temperature and substrate temperature over the range 100 – 260 °C, and for different tip speeds and heating times. It is found that thermal Marangoni forces and non-equilibrium wetting govern the nanometer-scale polymer flow, and that the polymer viscosity governs the mass flow rate. Polymer nanostructures are then characterized by AFM-IR. Nanostructures of polyethylene, polystyrene, and poly(3-dodecylthiophene-2,5-diyl) are fabricated with heights between 100 – 1000 nm, and find that AFM-IR can measure quantitative IR absorption spectra for structures as small as 100 nm with lateral spatial resolution below 100 nm. The sensitivity of AFM-IR is improved to measure the chemical composition of nanostructures roughly 10 nm tall by applying wavelet transforms to the cantilever response. The IR identification of the smallest polymer nanostructures is about one order of magnitude improvement over state of the art. This improvement is enabled by our insights into the time-domain and frequency-domain behaviors of the polymer nanostructure and cantilever during AFM-IR. The capabilities of AFM-IR are further demonstrated by measuring ohmic heating in highly Si doped InAs microparticles caused iii by localized surface plasmon resonances, demonstrating that AFM-IR is a versatile technique for measuring inorganic, optically absorbing materials in addition to organic materials. The ability to both control chemical patterning and analyze chemical composition at the nanometer scale provides a framework for designing and understanding increasingly complex chemical nanostructures for use in next generation nano-devices.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Felts, Jonathan

Contributors dc:contributor

• King, William P.
• Vakakis, Alexander F.
• Ewoldt, Randy H.
• Wasserman, Daniel M.

• atomic force microscope
• tip-based nanomanufacturing
• infrared spectroscopy
• thermal dip-pen nanolithography

Statement dc:rights

• Copyright 2013 Jonathan Felts

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/46637

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/46637