Nanoscale vacuum channel transistor with in-plane collection structure.

High quality nanoscale vacuum channel transistors (NVCTs) enable carriers to transport ballistically through the vacuum nanogap, achieving high speed and frequency characteristic which are essential for on-chip vacuum electronic devices. However, the studies to date have been largely confined to explore the common electrical performance, while the fast response characteristic of NVCTs remains a challenge. We report the fabrication of metal-based NVCT, with sub-100 nm vacuum channel and specific designed in-plane collection structure which can enhance the emission or collection efficiency of the electrons simultaneously. Importantly, the demonstration of a rise/fall time of less than 100 ns is achieved, which is compatible with those high-quality solid-state transistors based on low-dimensional materials. Moreover, the device can also retain excellent electrical performance, exhibiting a high drive current (>10 μA), low work voltage (<10 V) and high on/off current ratio (>104). The verification of fast temporal response of NVCT makes a significant step towards on-chip vacuum electronics with high speed and integration.