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The current–voltage and capacitance–voltage characteristics of Au–n‐type InSb Schottky diodes are measured at 77 K and discussed. In the sample preparation, anodic oxidation and etching in aqueous HCl are used, and the influence of annealing in H2 and N2 atmosphere is investigated. The effects of an interfacial layer between the metal and semiconductor are also discussed. The barrier height is estimated to be 98 to 149 meV. Annealing in a H2 atmosphere is found to increase positive charge within the interfacial layer, and therefore, a lower barrier height than that of a sample without annealing is obtained. It is found that annealing in a N2 atmosphere increases the negative charge within the interfacial layer and the barrier height. The interface state density is evaluated to (1.4 to 4.6) × 1012 eV−1 cm−2.

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Here, we present the design and test-operation performance of a low-temperature field emission (FE) system which can be employed to image and characterize the FE beam from low-temperature tips. Three radiation shields cooled by liquid helium and liquid nitrogen cryostats surround the FE tips and anodes completely. Once the FE system is cooled down to 5 K, experiments can run for more than 15 h without interruption. The design allows not only for the exchange of tips and anodes by load-lock equipment but also for the adjustment of tip–anode distance using a piezo-tube. Test runs in projection microscopy mode have presented clear diffraction-fringe patterns near the shadows of nano objects at temperatures from room temperature to 5.5 K, indicating that the system is well suited for the investigation of the coherence of electron beam from FE tip.