Open aperture microgated carbon nanotube FEAs

We grew the CNT inside 1.5 mum diameter open apertures lined with 0.25 mum of SiO₂ using DC plasma chemical vapor deposition (CVD) The oxide liner helped position the CNTs in the center of the cells and reduced the gate current by preventing the carbon nanotubes from contacting the gate. The concave-up curvature of the Fowler-Nordheim plot is probably caused by emission from CNTs with different field enhancement, due to varying diameters, lengths, and tips per aperture. We operated one array for six days at 65 V; after the first 24 hrs the current stabilized and remained above 200 muA. The likely causes for the initial drop include the evaporation and blunting of very thin CNTs by field desorption and the desorption of H₂O.