MANUFACTURABLE VACUUM FIELD-EMISSION DIODES

Realization of an easily manufacturable field emission device will be a key to the widespread acceptance of vacuum microelectronics technolo gy. Many current devices under investigation work well in the laborato ry but face serious manufacturing obstacles. With this in mind, a manu facturable cold field emission diode has been developed. The structure described here takes advantage of the edge emission cathodes similar to those developed by Gray et al., with the major difference being tha t the anode and cathode are not coplanar [H. F. Gray, Proceedings of t he Third Annual IEEE Vacuum Microelectronics Conference, Monterey, CA, July 1990 (unpublished)]. The ability to easily define, nonphotolitho graphically, the anode-to-cathode spacing during the fabrication proce ss allows control of the diode turn-on voltage over a wide range. Addi tionally, a symmetrical device geometry provides for increased field e mission area. Extensive device testing has shown current-voltage chara cteristics that follow the Fowler-Nordheim model for cold field emissi on over several orders of magnitude of current. In this work, various metals have been examined for use as the cathode and their differences noted. Finally, it should be reported that the structure developed he re will lend itself well to light emitting diode and triode devices.