High Current Silicon Nanowire Field Emitter Arrays

Arrays of n-doped silicon nanowire field emitters with a high aspect ratio are realized by a novel dry etching technique. Compared to the high current silicon emitters in the literature, the manufacturing process is much simpler and requires only a single photolithography step and two dry etching steps. The cathodes realized with this method exhibit a total current of 20 mA from an active area of 4×4 mm2, which is significantly higher than that for most known structures made from silicon and also represents good performance in comparison with other emitter types, e.g., carbon nanotubes. In addition to characterization in ultrahigh vacuum, measurements at 10−5 mbar are performed and compared with our recent silicon emitters. Compared to these cathodes, the structures with the nanowires exhibit at least two orders of magnitude higher current-carrying capability.