Date of Award
Doctor of Philosophy
Materials Science and Engineering
Philip D. Rack
Jason D. Fowlkes, Gerd J Duscher, Eric D. Lukosi
This dissertation addresses three difficulties with focused electron beam induced deposition preventing broader application; purity, spatial control, and mechanical characterization.
Focused electron beam induced deposition (FEBID) has many advantages as a nanoscale fabrication tool. It is compatible for implementation into current lithographic techniques and has the potential to direct-write in a single step nanostructures of a high degree of complexity. FEBID is a very versatile tool capable of fabricating structures of many different compositions ranging from insulating oxides to conducting metals.
Due to the complexity of the technique and the difficulty in directly measuring many important variables, FEBID has remained a niche technique for nanoscale fabrication and prototyping. The Achilles heel of FEBID is that, with few exceptions, the resultant structures are riddled with impurities. Also, the use of FEBID as a nanoscale 3D printing tool is limited and has historically been approached from a trial and error point of view
To address these issues, we have developed an advanced low-temperature purification method through a post process involving the electron stimulated reaction of O2 and carbon contaminates. This method is discussed in Chapter 1. We have investigated parameters involved in three dimensional FEBID, demonstrating control over those parameters to produce predicable shapes with high precision and complexity as described in Chapter 2. It is non-trivial to purify simultaneous during 3D printing, and so we have studied and developed a method to accomplish that using an in situ pulsed laser thermal anneal. Chapter 3 demonstrates this fully in situ 3D purification process. Finally, for emerging applications it will be important to know the mechanical properties of intricate structures created through FEBID. To this end, we have developed a method for the mechanical characterization of 3D nanostructures fabricated using FEBID. The mechanical characterization process, tools, and results are detailed in Chapter 4.
Lewis, Brett Bloxton, "Advanced Purification and Direct-Write 3D Nanoprinting Via Focused Electron Beam Induced Deposition. " PhD diss., University of Tennessee, 2017.