The preparation of field electron/field-ion emitters by ion etching

A new technique is described for the fabrication and resharpening of field emitters. This technique employs an ion gun and uses methods analogous to those used to produce thin foils for the transmission electron microscope. In this way it has proved possible to produce reliably sharp emitters of both metal and semiconducting materials and the technique is particularly useful when dealing with those materials normally difficult to electropolish or chemically etch. Applications lie not only in field electron emission and field-ion microscopy, but may also be relevant to the development of high current electron sources for use in electron microscopy.