Compound Silicon Field Emitter Array Cathode

As a novel electron source, filed emission array cathode possesses important application prospect in numerous fields for its small size, low power consumption, high response speed, as well as anti-radiation and broad temperature range. However, its defects of low current density and unstable emission characteristic have greatly limited its application space.In this dissertation, compounded silicon based field emitter array cathode was fabricated with new material and unique process on the basis of traditional micro-tip FEA structure. Polycrystalline silicon material with strong adhesion and high melting point were used as the high resistance basement of the tips. LaB6, with its low work function, high melting point, high conductance, as well as high stability to iron sputtering and chemical corrosion, was utilized to coat the emission tips in order to enhance the current density and emission stability.Our work contained process research of compounded Si based field emitter array cathodes, dynamic test and results discussion. At the start, fabrication technique of cathode array was studied in detail. An 800nm insulating layer was prepared on n-Si cathode floor by silicon thermal oxidation; a 200nm Ti-W gate was deposited by magnetron sputtering; the cavity array with 6um spacing and 1um aperture was fabricated by photolithography and then etched by chemical process; the Al sacrificial layer was fabricated by vacuum evaporation and p-Si tip foundation was prepared by electron beam evaporation. A compounded Si based field emission array with excellent emission topography was obtained after sacrificial cleaning process and LaB6 electron beam evaporation.Dynamic test of compounded Si based field emission arrays was carried out. During the test, the short circuit between cathode and gate was evidenced, which would be the emphasis of future research.Influencing factors to current density and emission stability were studied and discussed in the end, including incompletion of tip evaporation, abscission and fracture of tips, oxidation of cathode, and the abscission of gate, short circuit between cathode and gate, as well as micro-burs of the tip surfaces. Improvement suggestions to these problems were put forward in the end.