Proof-of-Concept Vacuum Microelectronic NOR Gate Fabricated Using Microelectromechanical Systems and Carbon Nanotube...

Area of Science:

• Microelectromechanical Systems (MEMS)
• Vacuum Microelectronics
• Nanotechnology

Background:

• Vacuum microelectronic devices offer potential advantages in harsh environments.
• Carbon nanotube (CNT) field emitters are promising for miniaturized vacuum devices.
• Existing microfabrication techniques can be adapted for complex vacuum electronic circuits.

Purpose of the Study:

• To demonstrate a fully integrated vacuum microelectronic NOR logic gate.
• To evaluate the performance and radiation survivability of CNT-based vacuum microelectronic devices.
• To establish a proof-of-concept for intricate vacuum logic devices in high-radiation environments.

Main Methods:

• Fabrication of a NOR logic gate using microfabricated polysilicon panels and CNT field emission cathodes.
• Integration of two parallel vacuum tetrodes using the polysilicon Multi-User MEMS Processes (polyMUMPs).
• Testing of a simplified diode device structure under gamma radiation exposure (45.6 rad(Si)/second).

Main Results:

• Successful demonstration of NOR logic gate functionality with parallel vacuum tetrodes.
• Transistor-like performance observed in individual tetrodes, though with low transconductance (7.6 × 10^-9 S) and unachieved current saturation.
• Asymmetric performance noted due to variations in CNT emitter characteristics.
• Functional demonstration of a diode device during gamma radiation exposure, indicating radiation survivability.

Conclusions:

• The fabricated vacuum microelectronic NOR logic gate serves as a proof-of-concept for complex logic devices.
• The device platform shows potential for applications in high-radiation environments.
• Further optimization is needed to address performance limitations like transconductance and asymmetry.