Approach for fabricating microgated field-emission arrays with individual carbon nanotube emitters

We propose an approach for fabricating microgated field-emission arrays (FEAs) with individual carbon nanotube (CNT) emitters. Beginning with the fabrication of microgated cell arrays, the process involves depositing a sacrificial layer at a glancing angle to close in the aperture that a small area catalyst can be placed on the bottom of the cells (for type A) or on the predeposited Mo tips (for type B); then, vertically aligned CNTs are grown by a dc plasma-enhanced chemical vapor deposition following a lift-off process. Scanning electron microscopy (SEM) images of both types of CNT FEAs show a large percentage of emitters with single, double or triple CNTs. For a 5×5 type B CNT FEA, at a gate voltage of 100 V, an average anode current reaches 1.4μA per cell while the gate current is less than 5% of the anode current.