Large area deposition of field emission cathodes for flat panel displays

Conventional emitter deposition for a Spindt-type field emission cathode (FEC) requires a very high tolerance in thickness uniformity using a planetary substrate fixture and a large source-to-substrate separation. Advanced FECs achieve a reduction in pixel switching voltage by reducing emitter and gate aperture sizes while maintaining current density by increasing the density of emitters. Furthermore, advanced FECs seek to scale substrate size from small areas (<30 cm(2)) to large (>500 cm(2)) areas, compounding manufacturing to the conventional FEC deposition process. A patented approach to design, assemble, and operate a coating system enables deposition of small dimension emitters over large areas through control of source divergence and sample positioning. (C) 1999 Elsevier science S.A. All rights reserved.