Pressure Sensitivity of Electron Emission from SiOx Tunneling Diodes and their Outstanding Emission Performance under Rough Vacuum

Abstract

AbstractOn‐chip electron sources with low pressure‐sensitivity and outstanding emission performances under rough vacuum are highly desired for developing miniature fully encapsulated vacuum electronic devices. Here, the sensitivity of electron emission from SiOx tunneling diodes formed in electroformed SiOx to the variation of ambient vacuum pressure from ≈10−4 to ≈102 Pa is explored. Electron emission from SiOx tunneling diodes is found to be insensitive to pressure variation when the pressure is lower than ≈10−1 Pa and exhibits fast degradation above the pressure, showing much lower pressure sensitivity than field emission sources. Despite emission current degradation above ≈10−1 Pa, SiOx tunneling diodes exhibit stable and reproducible electron emission under fixed rough vacuum up to 8 Pa, and good restorability after being repeatedly exposed to air pressure. By analyzing transport current of SiOx tunneling diodes under varying ambient vacuum pressure, the degradation of emission current above ≈10−1 Pa is attributed to the widening of insulating SiOx channel in the diode due to the transformation of Si conducting filament to SiOx with increasing oxygen partial pressure.