Nanoscale Vacuum-Channel Transistor

As the field of microfabrication advanced, it became possible to fabricate field-emitted electron sources, thereby paving the way for vacuum-channel transistors. The performance of a vacuum-channel transistor depends upon the field emission of electrons from the source electrode. [4] Due to the degradation of electrons source electrode, vacuum-channel transistors suffer from poor reliability.

Source: en.wikipedia.org