Complex Extreme Ultraviolet Imaging Reflectometry: Quantitative Lensless Imaging with Short-Wavelength Light in Reflection Geometries

Porter, Christina Lynn

Graduate Thesis Or Dissertation

Complex Extreme Ultraviolet Imaging Reflectometry: Quantitative Lensless Imaging with Short-Wavelength Light in Reflection Geometries Public Deposited

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Citeable URL: https://scholar.colorado.edu/concern/graduate_thesis_or_dissertations/4m90dv600

Abstract

The goal of this thesis is to demonstrate non-destructive, high resolution, quantitative imaging with special focus on extracting local composition vs. depth profiles that fully characterize thick, optically opaque samples in three dimensions. I will present a new technique called complex, extreme ultraviolet imaging reflectometry that is capable of such measurements. This thesis will cover the design and methodology for our new complex imaging reflectometer, the software we use to reconstruct sample compositions, and proof-of-principle experimental demonstrations of the full technique. The experiments presented here progress from longer to shorter wavelengths and from more static to more dynamic imaging geometries. The first demonstrates how quantitative information about a sample’s composition can be extracted from one ptychographic image collected on a first-generation 30 nm lensless microscope. This experiment serves as the primary motivation for the rest of this thesis. Subsequently, a new, second-generation lensless microscope that I and my colleagues developed to obtain more complete quantitative information is presented. This proceeds in several parts. First, our initial demonstration of reflection-mode ptychographic imaging at 13 nm on a tabletop microscope is presented. Next, our second-generation microscope is given dynamic capabilities that transform it into a complex imaging reflectometer: We add sample and camera manipulations under vacuum that allow us to collect reflection-mode ptychographic images at many incidence angles. The design and methodology for the imaging reflectometry instrumentation and reconstruction workflow are presented, followed by results from this new instrument at several wavelengths. This includes microscope verification images at 350 nm, traditional reflectometry at 13nm, full complex imaging reflectometry at 30 nm, and preliminary imaging at 13 nm.

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