Nanoimprint Lithography and its Applications in Photonics, Biotechnology and Energy Conversion Devices by Brandon D. Lucas A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Applied Physics) in the University of Michigan 2017 Doctoral Committee: Professor L. Jay Guo, Chair Professor Cagliyan Kurdak Assistant Professor Xiaogan Liang Associate Research Scientist Moussa N’Gom DEDICATION This is dedicated to everyone that has supported me along this journey. I thank God for your presence and support in my life! ii ACKNOWLEDGMENTS I would like to thank my committee for their support throughout this process. A special expression of gratitude to my advisor Professor Guo along with all members of the group both past and present. I am appreciative of the many collaborators with whom I have been given the privilege to work during my graduate study. This dissertation certainly would not have been possible without the generous support from the David and Lucile Packard Foundation and the Merck Foundation. Most importantly, this milestone would not have been possible without the almighty God who continues to provide for me in ways that are exceedingly and abundantly above all things that I could ever imagine. My wife (Neali) and daughter (London) are two of the greatest examples of his love for me. iii Table of Contents DEDICATION................................................................................................................... ii ACKNOWLEDGMENTS ............................................................................................... iii LIST OF FIGURES ....................................................................................................... viii LIST OF TABLES .......................................................................................................... xii -Overview of Nanolithographic Techniques ................................................. 1 Introduction ............................................................................................................................... 1 Radiation-based Nanopatterning ............................................................................................. 3 Immersion Lithography ........................................................................................................... 3 Extreme Ultraviolet Lithography (EUV) ................................................................................ 3 Fundamentals of Nanoimprint Lithography ........................................................................... 4 Defectivity ............................................................................................................................... 6 Mold Template Generation ..................................................................................................... 7 NIL Derivatives ..................................................................................................................... 10 Thesis organization .................................................................................................................. 11 References ................................................................................................................................ 12 -Plasmonic Nanoblock Arrays Fabricated Via Nanoimprint Lithography ........................................................................................................................................... 13 iv Introduction ............................................................................................................................. 13 Surface Plasmons .................................................................................................................. 13 Localized Surface Plasmons and Nanoparticle Synthesis ..................................................... 16 Methods .................................................................................................................................... 19 General Fabrication Methodology ........................................................................................ 19 Nanoblock Mold Fabrication ................................................................................................ 22 NIL Sample Fabrication ........................................................................................................ 23 E-beam Lithography .............................................................................................................. 24 Nanoparticle Array Optical Characterization ........................................................................ 24 Modification of Dielectric Environment ............................................................................... 25 Surface Enhanced Raman Spectra ......................................................................................... 25 Results ....................................................................................................................................... 26 Height Dependence ............................................................................................................... 26 Effect of Ti Adhesion Layer.................................................................................................. 27 Material Composition ............................................................................................................ 28 Bulk Refractive Index Sensitivity ......................................................................................... 29 Optical Dichroism ................................................................................................................. 31 Distance-Dependent Refractive Index Sensitivity ................................................................ 33 Estimation of SERS Enhancement Factor ............................................................................. 35 Probing NPAs using Spectroscopic Ellipsometry (SE) ......................................................... 37 Summary .................................................................................................................................. 41 References ................................................................................................................................ 42 v -Au Nanostructure Arrays for Plasmonic Applications: Annealed Island Films Versus Nanoimpring Lithography ...................................................................... 46 Introduction ............................................................................................................................. 46 Methods .................................................................................................................................... 48 Fabrication of Random NSA Samples .................................................................................. 48 Fabrication of Ordered NSA Samples ................................................................................... 49 AFM Measurements .............................................................................................................. 51 Spectrophotometric Measurements ....................................................................................... 51 Theoretical Modeling of Light Extinction and Field Intensity Enhancement ....................... 52 Results ....................................................................................................................................... 54 Characteristics of Random NSA Samples ............................................................................. 54 Characteristics of Ordered NSA Samples ............................................................................. 55 Modeling Results .................................................................................................................. 56 Conclusions .............................................................................................................................. 60 References ................................................................................................................................ 61 -Detection of Biomolecules Using Optoelectronic Biosensor Based on Localized Surface Plasmon Resonance ......................................................................... 64 Introduction ............................................................................................................................. 64 Theoretical Background.......................................................................................................... 66 Mold and Sample Fabrication ................................................................................................ 69 Mold Fabrication ................................................................................................................... 69 Sample Fabrication ................................................................................................................ 70 vi Methods .................................................................................................................................... 72 Results ....................................................................................................................................... 73 Conclusion ................................................................................................................................ 78 References ...............................................................................................................................