IMPROVED MONOLITHIC VACUUM FIELD-EMISSION DIODES

Realization of an easily manufacturable field emission device has been widely recognized as one of the keys to the widespread acceptance of vacuum microelectronics technology. Working to achieve this goal, many researchers have investigated edge emission cathodes similar to those developed by Gray et al. These efforts include work in the area of no nplanar edge emission devices reported by Weichold et al. and devices reported by Itoh et al. Based on that concept, this paper describes an improved nonplanar edge emission diode, suitable for monolithic integ ration. The structure described by Weichold has several interesting qu alities, including the ability to easily define, nonphotolithographica lly, the anode to cathode spacing during the fabrication process. Addi tionally, the unique device geometry provides several advantages over traditional structures. Unfortunately, this device does not lend itsel f well to integration, due to the difficulty of making electrical cont act to the cathode. An improved nonplanar diode design which addresses this issue has been conceived and manufactured. The new design has th e additional advantage of relying only upon standard manufacturing tec hniques for its construction. Preliminary device testing has shown cur rent-voltage characteristics that follow the Fowler-Nordheim model for cold field emission over several orders of magnitude of current. In t his work, various cathode sizes are investigated and several cathode a rray sizes are tested.