A Bipolar Vacuum Microelectronic Device

This report provides the first demonstration of a vacuum microelectronic device that utilizes both positive and negative charge states (i.e., a bipolar vacuum microelectronic device), thus enabling the possibility of device designs that are not previously possible in traditional vacuum microelectronics. In the same way that complimentary metal-oxide-semiconductor (complimentary n-channel MOS and p-channel MOS) were required in solid-state electronics before digital logic applications could be addressed, vacuum microelectronic devices benefit from a second charge state to realize many applications. This advance could enable integrated circuits for radiation-intensive environments (nuclear power facilities and space-based communications such as satellites) and high-temperature applications (engines and materials processing). A microelectromechanical systems platform was used to construct pentode structures with integrated carbon nanotube field emitters for electron emission and bias electrodes for separate electron- and ion-current modulation. Ions were generated via electron impact in an argon ambient, and devices were tested in both voltage sweep and pulsed modes. Current that is greater than 2 mA/cm² was modulated at the anode between ion and electron collection, demonstrating that this novel platform has the potential to foster a new class of bipolar vacuum microelectronics.