Bulk Molybdenum Spindt Field Emission Arrays

Abstract

This paper reports on a simple approach for fabricating modest aspect ratio field emission arrays (FEAs) directly from bulk molybdenum substrates via the use of fluorine inductive-coupled-plasma (ICP) etching. Compared to traditional Spindt array fabrication, through our outlined fabrication process all thin film interfaces have been eliminated reducing tip delamination during operation. The as-fabricated devices exhibited low turn-on electric fields (I = 100nA) of 1.21 V/μm. Arrays of more than 10$^6$ tips, with controlled inter-tip-pitches of 10 μm, have produced maximum currents of up to 140 μA (5.48 V/μm). Spatially uniform emission, that can be white light optically modulated, has been observed making our Mo-FEAs promising for use in long-term, high beam current continuous emission applications.