Oxygen plasma resurrection of triode type carbon nanotube field emission cathodes

• An oxygen plasma etch is performed on CNT Spindt type electron sources.
• Electrical shorting from the gate and substrate layers is reversed.
• Chip yield is increased by 71% due to the plasma etch.
• The plasma etch is a sample and highly effective method to increase yield.

The field electron emission of carbon nanotubes has been heavily studied over the past two decades for various applications, such as in display technologies, microwave amplifiers, and spacecraft propulsion. However, a commercializable lightweight and internally gated electron source has yet to be realized. Electrical shorting of the gate to the substrate is a common and problematic failure mode for Spindt type carbon nanotube electron sources, severely limiting their manufacturability. This work explores the novel use of an oxygen plasma etch to reverse this shorting. Plasma treatments on CNTs are commonly used to improve FE performance, but no work presents the use of a plasma etch to reverse shorting. The oxygen plasma etch is shown to be a simple and highly effective method to reverse shorting and increase yield of open circuit Spindt type CNT electron sources by over 70%.