Highly stable carbon nanotube cathode for electron beam application

The authors fabricated an optimized electron beam (e-beam) with a carbon nanotube (CNT) cathode and triode configuration. CNT emitters grown with a resist-assisted patterning process were used as an electron source. The gate mesh was aligned with the CNT emitter islands for a lower leakage current, resulting in a higher electron emission current and transmission ratio. Additionally, the width between CNT islands and the pitch between CNTs were optimized to enhance the electric field at the tip of the CNT emitters. With the optimized e-beam module, consisting of a CNT cathode and gate mesh, CNT pitch of 30 μm, dot size of 3 μm, line width of 210 μm, and gate mesh width of 75 μm, the emission current showed an increase of 165 times and operated for more than 500 h with DC driving. The optimized e-beam can be a building block for vacuum nanoelectronic devices.