Field emitter array mask patterning using laser interference lithography

Abstract

We have fabricated uniform arrays of 120-nm-diam dot masks on 300 nm centers using laser interference lithography. Chrome, cobalt, nickel, and germanium dot arrays have been fabricated. The density of these arrays is ≳109 dots/cm2. The standard deviation of the average dot diameter is 7.4% over a 5-cm-diam silicon substrate. The center-to-center spacing of the dot mask is determined by the laser wavelength and interference angle. Some control over the dot diameter is possible by varying the angle of the substrate during the metal deposition prior to liftoff. We have used a reactive ion etch with these metal dot masks to form single crystal silicon pedestals demonstrating that these structures are suitable for self-aligned gated field emitter array fabrication.