Characterization and fabrication of chimney-shaped metal field emitters

Abstract

A novel fabrication technology has been successully developed for chimney-shaped metal field emitters in order to improve the electrical characterisitcs of field-emission devices. This technology is based on anisotropic dry etching and sputtering deposition of metal film as well as wet etching of the attached silicon. It enables easy fabrication of chimney-shaped field emitters with excellent uniformity and high reproducibility. The anode current of the chimney-shaped Cr field emitter array (FEA) is 36.3 mu-A at the applied voltage of 1100 V and the threshold voltage V-T, defined as that for which the anode current I-n reaches 1 mu-A is 787 V. The chimney-shaped Cr FEA emits a current thirty times higher than that from the cone-shaped Cr-clad FEA at the applied voltage of 1100 V. This can be attributed to the presence of many sharp tips along the edge of the chimney-shaped emitter. The degradation phenomenon is not observed because compensation occurs between these many sharp tips. Another merit of this technique is that only one photolithography mask is needed during processing.