In this work we investigate the suitability of insulating coatings as electron tunneling barriers onDC micro hollow cathode surfaces. Our hypothesis is that with a sufficiently thin insulating coating of
sufficiently high dielectric strength, one might sustain the continuous current of a traditional DC glow
discharge through an insulator’s relatively high secondary electron emission yield at the surface, while
preventing surface charging through tunneling processes. We initially focus on aluminum oxide as a
well-understood material with mature atomic layer deposition (ALD) and other semiconductor
fabrication technologies. Several basic geometries are investigated, including planar disc cathodes and
tubular hollow cathodes. Electrical results are compared with simple analytical models assuming a
tunneling mechanism to allow DC current to pass through the insulating surface due to the applied
electric field imposed by the plasma sheath. Furthermore, we verify that conduction and sustenance of
cathode discharge not only occurs through tunneling, but also which thicknesses of insulating film are
optimal. Micro-hollow cathode discharge devices were successfully fabricated and scaling relationships
between number of pores were established. Later chapters cover the novel material 12CaO∙7Al2O3
(C12A7) which exhibits excellent room temperature emission and stability. Furthermore, early success
towards the fabrication of C12A7 by ALD has been completed in hopes of incorporation into micro
hollow cathode discharge (MHCD) devices in further work.