Vacuum Microtriode with Comb-Shaped Lateral Field-Emitter Array

A new vacuum triode with a lateral field-emitter array (FEA) has been fabricated, and its characteristics have been measured. The emitter has an array of 3-mum-wide-edged rectangular tips made of a 0.25-mum-thick tungsten film deposited on a quartz substrate with 9 mum pitch. The emitter-to-gate and emitter-to-anode spacings were 0.5 mum and 5 mum, respectively. Emission and triode characteristics were measured. A transconductance of about 0.7 muS/150-tips were obtained at a gate voltage of 110 V and an anode voltage of 150 V. Device structure and characteristics are described.