Field emission characteristics of single crystal LaB6 field emitters fabricated by electrochemical etching method

摘要

Single crystal lanthanum hexaboride (LaB6) field emission arrays with uniform tip structures have been achieved using the electrochemical etching method and the field emission characteristics are evaluated. A direct current voltage source is introduced in the etching process and phosphoric acid is used as the electrolyte solution. The SEM observation of the emitters reflects the feasibility of the electrochemical etching method for the fabrication of single crystal LaB6 FEA. The turn- on field of LaB6 FEA is low at 3.2V mu m(-1) and the emission current exhibits high stability during the 20- minute operation. Furthermore, even at low vacuum (> 1.5 x 10(-5) Torr) it still exhibits good emission properties and a strong ability to withstand the ion bombardment, which is useful for low operation vacuum microelectronic devices.