Extensions to solid-state superionic stamping with applications to generating structural color

Traditional top-down approaches for producing metallic nanostructures, despite being capable of producing arbitrary 2-D shapes, often use vacuum-based deep sub-micron lithographic fabrication technologies. This makes their use for single-use devices like chemical and bio-sensing substrates difficult to economically justify. In this thesis, I demonstrate a manufacturing pathway that only uses such techniques to produce a master. This reusable master, coupled with a unique and facile electrochemical imprinting process, Solid-State Superionic Stamping (S4), is used to produce several replicated metallic nanostructures, thus demonstrating an economically feasible manufacturing pathway for single-use, nano-enabled devices. The pathway begins with the production of a single master pattern. We use commercially available Two-Photon Lithography (TPL) to direct-write a mask on a silicon substrate. Shallow etching of the silicon substrate with this mask by the Reactive Ion Etching (RIE) process (or Deep Reactive-Ion Etching (DRIE) for deeper patterns) to produce a silicon master mold with the desired pattern. This master is used for hot embossing 〖(AgI)〗_x-〖(AgPO_3)〗_(1-x) glass, a chemically stable pure Ag-ion conductor with a low glass transition temperature, into a stamp. This glass stamp, in turn, is used in the S4 process, to electrochemically imprint the desired pattern into several substrates, thus directly producing the desired nanostructures. The different steps in this process flow are described along with their role and effectiveness in contributing to a high-fidelity plasmonic image reproduction. We use plasmonic image reproduction as an easy-to-visualize proxy for single-use devices such as plasmonic sensors and Surface Enhanced Raman Spectroscopy (SERS) substrates or Colored Infrared Reflective (CIR) patterns for radiative heating that require nanopatterned metallic structures. It demonstrates a process for replicating a picture by a set of metallic structures that plasmonically produce the desired colors locally. Finally, I explore the application of S4 within the damascene process to replace copper with silver, effectively removing the need for traditional chemical-mechanical polishing (CMP). This approach simplifies the damascene process, offering a cleaner and more efficient patterning method while preserving the structural integrity of the designs.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Illinois Urbana-Champaign

Year dc:date

2025

Author dc:creator

• Qian, Boqiang

Contributors dc:contributor

• Ferreira, Placid
• Kapoor, Shiv
• Cai, Lili
• Zhao, Yang

• Electrochemical etching
• Nanoimprint lithographyNanopatterning

Statement dc:rights

• Copyright 2025 Boqiang Qian

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/129172

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F129172