Abstract

Energy Dispersive X-Ray Spectroscopy (EDS) is a technique used to analyze materials to determine their elemental makeup. This technique is used extensively in the semiconductor industry, metallurgical industry, biology, chemistry, materials science, and other fields. EDS detectors are often attached to scanning electron microscopes (SEM) or transmission electron microscopes (TEM) and are actively cooled by liquid nitrogen or Peltier devices. A thin membrane, or window, is fitted to the front of the detector which allows for an airtight seal as well as transmission of x-rays. The challenge for these windows is maximizing the transmission of x-rays while maintaining mechanical integrity. Carbon is an element with a low atomic number and has several allotropes that have attributes desirable for an x-ray window. Amorphous carbon has good chemical resistance as well as being able to be sputtered, a low temperature process. Sputtered amorphous carbon is characterized in this work, including sputtered amorphous carbon that is used as part of x-ray windows. Part of this characterization involved using bulge testing. A bulge testing device was created at BYU and this is presented here. Additionally, this device was used to characterize thin films as part of this work. Graphene is a single layer of sp2 bonded carbon atoms in a plane. It is one of the stiffest materials known, as well as having an extremely high tensile strength (> 200 times steel). Single layer graphene has not been able to span the dimensions needed for use in a detector window, but many-layer graphene (MLG, a film with > 10 stacked layers of graphene) has been shown to span mm size openings. Many-layer graphene films were grown using chemical vapor deposition (CVD) on nickel substrates and suspended over different sized openings as well as on a silicon support structure. A description of synthesis and characterization of these films are presented here. Also presented is additional work to improve the fabrication of these MLG films by developing improved nickel substrate surfaces.

Degree

PhD

College and Department

Physical and Mathematical Sciences; Physics and Astronomy

Rights

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