Electron Emission from HFC(100) Tip at Various Temperatures

Abstract

We investigated the emission characteristics of a hafnium carbide: HfC(100) single crystal tip at various temperatures toward finding a candidate of next-generation emitters for scanning electron microscopes (SEMs). The emission mode changed from cold field emission (CFE) to thermal field emission (TFE) and finally to Schottky emission (SE). The energy width of the emitted electrons was 0.2 eV in CFE, which became larger in TFE and then small again in SE. The emission current noise was small except for high temperature TFE, and the emission had high stability in electron gun of the SEMs. The high monochromaticity and stable electron emission are suitable for high-resolution SEMs.