P-Type Si-Tips With Integrated Nanochannels for Stable Nonsaturated High Current Density Field Electron Emission

Abstract

Gated p-type Si-tips with individually integrated nanochannels were developed for stable nonsaturated high current density emission. Typically, a current up to 44 μA (~7.64 A/cm²) was obtained at 136 V from a 5 x 5 array. The current stability test (80 mins) showed an average current of 14.63 μA at 125 V (~2.53 A/cm²) with a standard deviation of ~0.59 μA and a coefficient of variation of ~4.04%. No tip profile change was observed after all the tests, which suggests good reliability. The Joule-heating of the emission current resulted in a temperature increase at the top-region of the tip, promoting the local carrier generation and enhancing the emission. Meanwhile, the nanochannel limits the transportation of generation holes, which conversely suppresses the net carrier generation and stabilize the enhanced current. Such a dynamic equilibrium mechanism brings about negative feedback and protects the tips from overheating and current overloading. Emission from the excellent tip emitters was restricted and more tips contributed to emission, leading to a stable nonsaturated high current density emission. The work provides a new opportunity for developing high performance Si-tip field emission electron sources.