Alloys for liquid metal ion sources

Abstract

Alloys suitable for use in liquid metal field ionization ion sources are provided. Such sources include an anode electrode for supporting an ion emitter comprising an alloy in the liquid state. The source further comprises means for generating an ionizing electric field and a reservoir for the liquid metal, ions of which are to be emitted by the source. The alloys are selected from the group consisting of (a) metal-metalloid alloys comprising about 10 to 30 atom percent of at least one metalloid element, the balance at least one transition metal element, (b) early transition-late transition alloys comprising about 30 to 85 atom percent of at least one early transition metal, the balance at least one late transition metal, and (c) Group II alloys comprising about 35 to 80 atom percent of at least one Group II element, the balance at least one metal element. Ions generated in liquid metal ion sources form a high brightness ion beam, which permits focusing a beam of emitted ions to a submicrometer spot. The ions may be used to alter material properties by ion implantation such as to dope semiconductors, to form ohmic contacts, to improve wear and corrosion resistance in metal surfaces and by sputter etching thin films such as metals, dielectrics and semiconductors.