NEEDLE-SHAPED EMITTER OF FIELD EMISSION TYPE LIQUID METAL ION SOURCE

摘要

PURPOSE:To smooth feeding of a liquid metal to the tip of a needle-shaped emit ter for giveng high performance and high reliability by forming the needle-shaped emitter in a shape, in which a change of the side shape from the columnar part to the conical part or from the square pillar part to the pyramid part is gentle without any steep boundary. CONSTITUTION:Either one of conductors having high melting points such as boride TiB2, CrB2 compound boride BN-TiB2, carbide TiC or the like is used for an emitter material. And, for instance, a columnar piller 11 having a square section is cut out from a parent metal 10, followed by being machined into a columnar pillar 12 for further being machined into a needle-shaped emitter 13 by mechanically grinding the tip side thereof. Said needle-shaped emitter 13 is further machined into the needle-shaped emitter 14 having a smooth boundary by mechanically grinding the boundary part changing from the columnar pillar to a cone. Thereby, a liquid metal can be fed smoothly to the tip for obtaining the stable ion emissive properties while making it possible to emit an ion beam with the taking-out voltage of low threshold value due to a sufficient amount of supply of the liquid metal serving as an ion source.