Reliable High Performance Carbon Nanotube and LaB6 Nanowire Field Emission Cathodes for STEM

79658B The reliable fabrication of high performance point electron sources is required for scanning transmission electron microscopy (STEM) systems with brightness greater than 109 Amp/cm2/steradian at an extraction voltage of 100 kV. Conventional point sources require a high vacuum for stable operation, and tip failure occurs by vacuum arcing and unstable emission due to atom migration. This project will develop technology for making point electron sources for scanning transmission electron microscopy by the dielectrophoresis process (DEP), which can assemble high performance point electron emitters on metal supports with controlled length and orientation. Phase I will demonstrate reliable production of high performance electron point sources by: (1) controlled fabrication using the DEP process; (2) micro-mechanical fabrication of single point sources; and (3) synthesis and assembly of nanowire point sources. Commercial Applications and Other Benefits as described by the awardee: The fabricated high performance point electron sources are expected to be used in STEM to replace the tungsten cold field emitter and other cathodes with improved resolution. They also should find use in other high resolution electron beam based instruments, like scanning electron microscopes, electron beam lithography machines, and e-beam deposition instruments to meet increasing demands from the semiconductor, nanotechnology, and life sciences fields to improve processing resolution and speed.