Field-emission properties of patterned ZnO nanowires on 2.5D MEMS substrate

We fabricated a nanowire-based field-emission display (FED) device on a 2.5D substrate using a photolithography, lift-off, thermal-evaporation, and plasma-etching process. We first fabricated a 3×3 array of microholes (diameter = 400 μm and depth = 50 μm) on a Si substrate and fabricated ZnO nanowires inside the microholes by using a thermal CVD process. The field-emission pattern image of the 3×3 array of microholes was clearly apparent. The threshold emission field was ca. 5.6 V/μm and we obtained considerable brightness when the applied voltage was 1900 V (i.e. 6.3 V/μm). Because the fabrication processes used in this study are standard semiconductor fabrication routes, the study suggests the feasibility of mass producing a nanowire-based FED device.