Scaleable Carbon Nanotube Field Emitters for Scanning Electron Beam Instruments

Many industries, including the semiconductor industry (which drives the global economy) and the emerging nanotechnology industry, depend on scanning electron beam instruments ¿ such as field emission scanning electron microscopes (FE-SEMs), Schottky emitter based SEMs (for example, critical dimension SEMs), and transmission electron microscopes (TEMs) ¿ to develop new processes and products, control existing processes, and stimulate new innovations in materials science. All of these applications require improved electron beam micro-characterization, especially improvements in the spatial resolution, signal-to-noise ratio, and processing speed of these imaging tools. These requirements can be met by improving either the electron optical column or the electron source. Although electron optical columns have improved significantly in the last 10-15 years, the field emission source itself has remained basically unchanged. Therefore, this project will demonstrate the utility of nano-sized, high-aspect-ratio, cylindrical, carbon-nanotube (CNT) field emitters for Scanning Electron Microscopes (SEMs) and Scanning Transmission Electron Microscopes (TEMs). These CNT field emitters will offer high brightness, low energy spread, small emitter size, high emission stability, long emitter lifetime, and suitability for commercial fabrication . Phase I will design optimal carbon nanotube (CNT) field emitters with geometries for use with scanning electron beam instruments; demonstrate the feasibility of fabricating carbon nanotube field emitters on metal substrates (wires) that can be integrated into SEM and TEM guns; and demonstrate field emission figures-of-merit for the CNT field emitters. Commercial Applications and Other Benefits as described by the awardee: Carbon nanotube field emitters on metal substrates (wires), which can be integrated into SEM and TEM electron guns, would provide improved resolution performance in materials science, biology, medical research, and forensics.