Platform for integrated vacuum microelectronic circuits

Vacuum devices are preferred to solid-state for applications requiring radiation stability, a wide range in operating temperature, or high power at high frequency. However, difficulties associated with integrating these devices on the microscale have limited their development. We describe a monolithic vacuum microelectronic integration platform based on freestanding polysilicon MEMS devices with integrated carbon nanotube (CNT) field emitters. A four panel vacuum microtriode consisting of a cathode, extraction grid, control grid, and anode is being developed as the key active circuit component of the platform. We also describe efforts to develop cathodes with sufficient emission stability and lifetime for practical circuit implementation. Lifetime of CNT-based cathodes is being optimized through use of multilayer catalysts and CNT coating processes. This platform has the potential to enable high performance, integrated vacuum microelectronic circuits including amplifiers, oscillators, and logic circuits.