| With the flat panel display industry eclipsing ;MWCNTs were grown in a chemical vapor deposition (CVD) reactor by exposing nickel nanoparticles, formed by annealing thermally evaporated nickel thin films under 20 cm3/s (STP) hydrogen flow at 1173 K for 5 minutes, to a mixture of 6 gases (CH4, CO2, CO, H2, and H2O) with a gas phase carbon activity of 20 at 900 K and a total flow rate of 20 cm3/s (STP) for 90 minutes. Spaghetti-like MWCNTs grew on substrates with 10.2 +/- 1 nm nickel nanoparticles in a gas mixture with O/H ratio 0.1. An increase in the O/H ratio to 0.5 resulted in the formation of both spaghetti-like MWCNTs and straight MWCNTs. Substrates with 6.1 +/- 1 nm nickel nanoparticles and the same O/H ratio, resulted in preferential growth of straight, uniform diameter MWCNTs. Thus, the fabrication of straight, uniform diameter MWCNTs with CVD requires a nickel nanoparticle diameter less than 10 nm and an O/H ratio of 0.5.;Arrays of 43 nm wells were obtained through electron-beam lithography (EBL) after optimization of the thickness of the resist layers and e-beam dosages in addition to hard-baking of the resist. Subsequently, catalyst was deposited within the wells to enable site-specific growth of the MWCNTs. Hard-baking prevented the resist layer from collapsing during the EBL process, but also prevented its removal during lift-off. Electrical characterization of candidate devices within a custom-built high vacuum chamber showed the need for voltages above 162 V in order to achieve measurable emission. |
